Here are some old knives that are pushing present day boundaries long ago.
melon tester with a shirt pocket clip:
pen knife with "ears" patented in 1892 by Walter William Pellet
I found my posts from the earlier topic and thought I'd put them here as well since they show some examples...
"Here's one example of an old shadow easy opener..."
"Here's one made in the USA..."
"I'd need to dig for that patent but sounds right about the patent, Lloyd.
Regarding Mike's knife...
Patterns are typically defined by handle shape and blades. In some cases, the handle alone defines the pattern. For example a Wharncliffe knife is defined by the shape of the handle and doesn't always have a Wharncliffe blade. And the big bolster differentiates a barlow from a regular jack.
Mike's knife is pretty much straight up "Easy Opener" with the twist that it's also a "shadow". Knives without any bolsters are "shadow" patterns (2nd down on the left). It's a "shadow" version of an "Easy Opener" (3rd from the bottom in the middle column). If it didn't have the easy open notch, it would be a "swell end jack" (3rd column).
For some reason, knives without bolsters seem to get lumped in as sodbusters or modern knives. For example, I don't think the "Proper" is a sodbuster at all but it often gets compared to one. I'm not sure what it is.
I do think Mike's knife is traditional. I know what pattern it is."