That's the booklet I mentioned in my posts on the other message boards where you also asked this question. He makes that iron ferrule out of very thin metal - like cut from a coffee can. And he wraps it around and then kinks the ends to then fit down into the slot in the handle on either side of the blade. I have not personally seen or heard of this last little part anywhere except in his book.
Personally, I use 18 or 20 guage sheet to make my iron band. And it only goes around without any extra tucked down into the wood handle - leaving just a slot for the blade to pass through. And you can do the same thing with some Iron conduit - just cut off a band and then cut through it to create that slot for the blade.
The key feature to get right is to have the hole for the rivet/pivot pin drilled slightly towards the open slot instead of dead center. Both the hole in the blade and handle need to be drilled like that. This gives room for the blade to swivel in and out. That is the most critical part of making your own penny knife.
There is a good discussion (with documentation and scale drawings) of penny knives in Mark Tully's first booklet The Packet. Actually, all 4 of his booklets are well worth getting - no matter what time period you might be doing. Lots of great info.
The French version of an inexpensive folding pocket knife is shown on that Trade Goods of New France web site. It doesn't have the metal band, and the handle generally isn't rounded/turned. Just a wood/bone/antler slotted handle, a blade with a little "tab" on the top/back to stop it from opening up too far, and a rivet pin w/wo washers. Usually called a jambette in written documents. There are some versions of it with a locking spring riveted onto the back of the handle, but I do not know how far back that variation can be documented.
Mikey - that grumpy ol' German blacksmith out in the Hinterlands
