Mr. Lander -
You've either bought a 'pig in a poke' or you have a very simple situation. Let's assume the best, especially since it was working when you bought it.
Hint #1: Since you may be new to Brit bikes let me first tell you that Brit bikes must be in neutral to crank, unlike many Jap bikes. The clutch will break free, but the rear wheel will continue to turn which some people may construe is a frozen clutch. So the REAL starting drill is: a) find neutral, b) break clutch free, c) crank bike.
By 'break the clutch free' we mean that 1 (or at most 2) quick jabs on the k/s lever will result in the lever going all the way down w/o the engine turning over. This is provided the bike has been riden within the last week or so.
Hint #2: Buy a shop manual
and do a complete "major clutch adjustment". These bikes need this every Spring anyway, so it won't be a waste of your time.
These two hints cover 90% of all newbie clutch issues. If you'll do these then contact us back with the results, we can then direct your efforts with more focused (read: less costly) results.
In my professional opinion, any disassembly of the primary case and clutch basket at this early stage is a waste of your time and money, and great riding weather. Besides the girls are already stacked up down at the corner waiting for your new Triumph's arrival. :p
Hope this helps! :bigt: