Dating stanley plane blades
The body and frog seem to be Type 5, but the adjuster and iron,as you said, seems to have characteristics of Type 6. The flat-top Bedrocks were all marked "Bedrock" on the bodies, and were introduced in 1911. They were often replaced in the days that a workman used his hand tools all day, every day.I've read that some Stanley planes are a mix of types, as changes were made and old parts were used on newer planes. I think that, as you suspect, someone cut the sides down. I've worn out new plane irons in a number of planes, though not yet quite a full blade in a #8.But my few brain cells didn't pull that thought off at the time needed.Maybe I can get the moderator to move this, or perhaps if the woodworking moderator can take it.BTW - Stanley did not care about "type dating" planes or any other tools.All they cared about was using up inventory and selling the heck out of it.Mine wasn't much better when I bought it at a boot sale, it will take a shaving like a net curtain now, good exercise too!
Almost all of Stanley's production up well into the 20th C was on the subcontractor basis (piece rate).The "type studies" were evolved by later scholars to help sort out the history/evolution.But again, back at the factory Stanley was only interested in selling product and avoiding waste.An alternate possibility is that someone who had the means to machine the tops of the cheeks flat (admittedly, they could have been hacksawed and filed), may have decided to add the frog with a lateral lever to an earlier plane. It could also have been "completed" from parts in the last few decades merely to make it usable or sale-able.Perhaps after dropping and breaking the donor plane. The person who completed it could also have chopped the top in hopes of fooling a casual buyer into thinking it was a Bedrock.