Good question- and I don't know....I do know that a lot of the weight is actually from the bridge unit and the pickups and not necessarily the body itself......I think replacing the bridge with something comparable in mass but not necessarily the weight is doable - the pickups are the issue: because those pickups themselves and its unorthodox wiring is what makes T 40s and 45s so special.....sure, the T 40 can definitely sound like a Ric but it can also sound a lot like some Alembic instruments- not a bad feat for a passive bass.......as a side note, there was a thread a few months ago about "What is the most hi fidelity passive pickup made?" ...after a few pages of all the usual suspects, I responded Peavey T 40/45 pickups ( because I really think they are) but was surprised how few Likes I got......so either I'm wrong about that or just most folks are unfamiliar with the magic of those pickups