As far as I know, Gerber didn't list exactly what steel they used until recently. High carbon stainless, steel that cuts steel, "mystery metal" among others have all been used in ads, literature, general talk and discussion to describe Gerber blade steel.
What I do know is-
the nail nick ceased to exist in the LST line around 91-92. I'm not 100% sure, but I believe that ended 440 use in blades as well. The 420HC in use today is good, but ain't nothing like the old LST's.
I carry one that my wife bought me in 2015 for work every day.
It's held up, but it shows how much it's had to be sharpened.
The one carried from the late 80s till I got the new one had been lost, found with the tip broken by somebody else, retipped on a concrete slab (the only thing I had when I found it in a guys toolbox on the job), and it barely shows how many times it's been sharpened in it's 20+ years of service.
It's very true when you say they don't make em like they used too. The fit and finish started to suffer a little after Fiskars bought the company, but around 93-94 when they went to the GERBER/400 Tang stamp they sorta 'redesigned' the LST.
The nailnick, 440 stainless, the hairline gap between blade and lock were gone. They changed the thickness of the blade and lock too. I recently sent an early camo LST hoping to get a new blade on it. They weren't able to do it because of the thickness difference.
With the blade not being as thick, the zytel handle was thinned down. The ' butt' is also a tell. Older LST's are smooth. The newer knives have a 'buildup' in the middle that wasn't taken off. It's the same knife, but different.
I waited until now to holler back because I was waiting on my friend at Gerber to email some information to me. I can't figure out why I can't upload the info, but it pretty much says the same thing. He resent the original LST info sheet that mysteriously disappeared when I swapped phones. The other is some info on the knives the first LST's were modeled after.
On the first, 440 is listed. On the second one, high carbon stainless is the choice.
Hopefully I can figure out how to upload it. When I do I'll put both in the history section.
I also need to thank you for your story. Never got the chance to meet Mr. Collins, wish I had. He was a genius at perfecting simplicity. A bunch of knofe companies still using his designs and patents today are proof of it.
And I'm far, far and away from an expert at anything. I got lucky and can remember a ton of useless information.
If I can be of any further service, holler at me.
My name is Mud,
But call me Alowishus Devadander Abercrombie
That's long for Mud, so I've been told