Historicaly, for all us old farts (how did I get old?) it was 'level 1' and 'level 2.' So TRO25 stuff (before it became TRO39) was all level 1, and all the SL and modern stuff was all equaly 'level 2.' Clan tech was actualy just a difrent sort of 'level 2' and anything experamental was 'level 3' weather Clan or IS.
Now, its about tech letters, so each bit of tech is rated with a letter, and a mech is the rating of the highest bit of tech. Most succession wars I think rates as D (some as C), SL stuff tends to be E, and very new prototypes F. But, I don't have that book on me at the moment, so that's just memory.
The old levels, however, are largely replaced by "Introductory rules" and "TW rules." That is to say, anything in the intro rules set or the quick start rules or whatever it is (all 3025 stuff) is "Introductory rules tech" or "intro tech," where as "TW rules" includes the full suite of what is in Total War, but not Tac Ops or anything else.
The problem with most of these is that they don't difrentiate between the tech of 2750 and the tech of 3150. So, its known that the LB10 predates the LB20 by four or five centuries, but they're not really a difrent level of tech by the rules, which care more about play ballance and complexity.
So, Dave's rules (I think you mentioned he came up with the Tech I thing) are meaningful as a devide.
But, I'd take a good hard look at the relitive FP values. Going from SL era tech to SL era tech with ER MLs and LGRs and RACs is a comperitively small jump, compared to going to full Clan tech. Some of the really good stuff (C3? stealth?) or experamental stuff might rate a higher FP level, but for the vast bulk of it, I'd caution against it. There's a reason they were so hot to put the Devistator and Pilliger back into production, after all, and even in the 3150 era no one will ever turn one of thouse mechs down, unless they can get a Dire Wolf.