The modern metal block plane was an artefact of the Victorian period. I mean different types of small metal planes did exist before then, like the British chariot plane, but they did not evolve from some wooden plane forerunner. The size of wooden planes has always been limited by the material they were made of – wood. Small wooden planes can be constructed, but their function would be constrained by the natural limitations of the wood. This is the reason why you won’t see many wooden block planes, even in places where wooden planes are quite common, e.g. Germany. Note that the discussion here is focused on a wooden equivalent of a traditional block plane with a bed angle of 12° or 20°.
One of the main reasons for the lack of wooden block planes lies in their construction. Wooden planes typically use a bevel-down blade configuration. In a bevel-down plane, the blade typically rests on a 45° wooden bed. Because the bevel sits behind the edge, the cutting angle is fixed at 45°, even though the bevel on the blade could be 25°. This is not a great angle for planing end-grain with a block plane. Bevel-down planes have limits to their bed angles (ca. 35°) before clearance becomes a real issue. Block planes, on the whole use a bevel-up configuration. In a typical low-angle metal block plane, the blade is bevel-up, where the bevel leads into the cut, contributing to the cutting angle. If the bed is low, typically 12°, the effective cutting angle becomes 37° once the blade angle of 25° is factored in (a much better angle for end grain). The bevel-up design was introduced to lower the bed-angle in order to make end-grain planing easier, because it minimizes tearing end-grain. A “normal” metal block plane with a bed of 20° + 25° blade will create a 45° cutting angle.
Now, it is possible to have low angled bed in a metal plane because the integrity of the metal body structure allows it. For example the precursor to the block plane, the metal chariot plane often had bed angles of 12-16°. However it is almost impossible to reproduce low bed angles in most woods, due to the tenuous nature of the material – therefore it is nigh impossible to have a wooden bevel-up block plane. Figure 2 shows a mock-up of a wooden block plane with a normal 20° bed, and explains some of the structural issues. In the tool epitome Antique Woodworking Tools, by David R. Russell, there are two planes (a late 19th C. chariot plane and an 1830’s mitre plane), both made of boxwood that have pitch’s of 21° and 20° respectively. The caveat is that both are reinforced with metal near the mouth of the plane.
If you look through one of the older E. C. Emmerich catalogues (1930-1950s) from Germany, there is little or no mention of a wooden block plane. At some point one did appear in the catalog, and is still made today, the 649-P Pocket plane. It is likely one of the few modern attempts at a wooden block plane, and is unique in that it’s blade is bedded at 50º (York pitch), ideally suited to hardwoods. But the lack of low-angle block planes in Germany meant that American-style metal block planes were utilized from early on (this may have been why Kunz, was so successful in manufacturing metal planes in Germany).
working by hand 
I think that the reason you do not find many wooden block planes is that you are looking at the wrong things…
Our modern iron “block plane” is the iron evolution from the wood bodied “strike block plane”. If you look for strike block planes you will find many more of them.
the 12 degree angle would not hold up well but 20 degrees does. and they were used with “strike blocks” to trim miters, squares, other angles etc.
they were frequently made with a mouth closing block in front of the blade so that when you had to refresh the sole you could close the mouth back up.
the Stanley #9 is the first plane that I know of that was made mostly of metal to do this job. Once they switched to a steel sole the 12 degree angle was workable.
Which is why the newer series goes from 3 to 8 then skips to 10 (the jack rabbit plane). The #1 appears to have been a salesman sample, the #2 was for training children, the #3 seems to be the smallest of those planes that an adult can use. I still have not found a #9 for my collection.
If you haven’t already; check out “Patrick’s Blood and Gore” he lists every plane Stanley ever made.
be well
Karl
I think the “strike block plane” was first described by Moxon in Mechanick Exercises, but the pictures were likely copied from Félibien’s “Principes de l’architecture, de la sculpture, de la peinture, etc.” from 1676, in which it is a “varlope à onglet ou anglée” was akin to a miter or angled joint. There are a lot of mitre planes out there in the ether, because they have been around for a long time, used for things like shooting end-grain. Now while I think they may have contributed to the design of block planes, I don’t believe they were core origin. For starters, these planes are typically circa 10″ in length, so much longer than a block plane. The Stanley No.9 was designed by Leonard Bailey, and was likely based on one of the Spiers infill mitre planes of the period, adding his own innovations, and likely producing a less expensive product than the imported Spiers (prior to the designs being bought by Stanley). This was a miter plane, even though in 1867 it was advertised as “Bailey’s iron block plane”. This was followed by the No.9½, which was designed as a smaller version of the No.9, however the concept was likely based on existing block planes, i.e. those manufactured by Birdsill Holly during the 1850s, which were the first cast iron block planes in North America. I based my discussion purely from the description of a block plane, i.e. the rational that there are no 6-7″ wooden block planes. In all likelihood the metal block plane was the amalgam of ideas from miter planes, chariot planes, existing designs, and the genius of Leonard Bailey.