Hi John -
One easy way to tell a very early one - look for an example that does not have metric demarcations on the rule -
Also, the knife blade is very specific to the age - they changed the knife grind/shape several times, and there are nuances to the phillips screwdriver.
The first Leatherman tools were all made for Cabelas and those are very rare to find.
There are also variations in the plier jaws, and the pivot size and lettering.
One thing about the Leatherman tools is that they made large batches of all the tools, and then pooled the parts in bins, so there are literally hundreds of variations, since any variation of tool could be assembled over the course of several months or years based on what was pulled from the bin.
Pictured here is the oldest example I have, from the late 80s.
This shows the blade shape of a very early, second version -
On early versions, the phillips screwdriver was offset inwards, and on later examples it was reversed to be offset outwards.
And what I believe to be an early original sheath -
Very early on, some components were made in Japan, and on some of these early PSTs you will find hollow rivets, and these models are quite collectable as well -
Here you see an early USA version with a hollow-rivet Japan version
Here you can see the Japan version has a knife blade stamped "Japan". You can also see the variation in the Letterman lettering and the trade mark registration stamp.
You can still find great deals on these, since most don't know how to tell an early from a more common later. You can buy these for under $40 if you are lucky and see one before it get's snapped up!
Beware ye who enter here, as collecting these can be very addictive!
(edited to add) - I am new to collecting these and my "knowledge" is gathered from the internet, so don't bet lunch on my facts...
best
mqqn
