Very interesting knives.
Before I continue I should have mentioned in my earlier post that you need to be a paying member (Gold or higher) of this forum in order to ask for a monetary valuation on your knives. To learn more about this click on "Paid Subscriptions" in the blue banner at the top of the screen.
Here's what I can tell you about those two knives-
They were made in Maniago, Italy. Maniago has been a knife-industry town in Italy going back hundreds of years. They are basically the world capital of Italian switchblades, with several different makers/brands producing knives, both under their own names, and for a variety of foreign importers.
Like you mentioned the first knife pictured is called a "swing guard". The type of blade is called a "swedge". The handles are cow horn. I believe the knife may have been made in the early 1960's. As far as who specifically in Maniago made the knife, if there are no other markings (name/logo) on the blade, it might be difficult if not impossible to know who made it, because like I said, there were many makers producing knives in Maniago.
The second knife is called a "transitional". "Transitional" refers to a period of time in Italy when stiletto switchblade makers transitioned from one type of stiletto switchblade to another. I'll try and explain-
Really old Italian stiletto switchblades had what is known as a "pick lock". The pick lock was a type of blade locking mechanism very similar to the one on your second knife (round-ish head, hole in the middle), except with a pick lock a person had to grab the edges of the lock head with their fingers or fingernails and manually pull it back to release the blade. Basically they had to "pick" at the lock with their fingernails. Pick lock heads were sometimes oversized, and had beveled edges making them easier to grab.
But pick locks could be difficult to unlock, so the Italians came up with a different type of unlocking mechanism that was easier to operate, this is called a "swivel bolster" (your second knife is a swivel bolster). The metal parts above the handles, the parts that the blade pivot pin passes through are the guard bolsters. With a swivel bolster knife, the front/button-side guard bolster can be rotated (swivel) by pulling down on the rear guard point, and this causes the rear of the bolster to push the lock out and away from the blade.
So, your second knife is known as a "transitional swivel bolster". It also has a swedge blade and horn handles (either cow or buffalo). I would also estimate that the knife was made in the early 1960's. But again, without any other blade markings it may be difficult to identify the specific maker.
There may be other members here who are more knowledgeable and who might know better than I when the knives were made and who specifically made them. But this post represents the limit of my knowledge regarding your knives.
I can also tell you that the knives are somewhat rare, specifically the swing guard. And that both knives are sought after by collectors of vintage Italian switchblades.
If any of the knives you've mentioned don't work, and if you are interested in having them fixed and restored as good as new, you should contact Bill DeShivs. Mr. DeShivs is a member here, and he is a leading authority on the repair and restoration of vintage Italian switchblades in the US, perhaps THE leading authority. He has a website- billdeshivs.com
Although I can't talk dollar value, having any non-functional knives repaired/restored by Mr. DeShivs would definitely and significantly increase their value and desirability among collectors.
Thanks for sharing them

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