Why oh why would you want blocks on a P?! I don't think much of the basses, especially when Nash are out there too, although the Tele/Les Paul Jr hybrid guitar they make has something about it, shame the pickup is mounted so close to the bridge.
This is a Gibson thread! Lol. The Jazz was a non export CIJ 66RI that has since been sold. It had a metal nut, Badass II and a pair of one off pickups that were modelled on the Geddy Lee sound. She was a beauty! Dot and bound neck and everything. I just never liked the way jazzes sit in rock mixes and the neck was a bit thin for me.
T-40s are incredible basses. I have two (one blade one toaster). I really don't know what to say about them other than incredible. I favour the blade because of the sculpted body shape, it has more bite too, while the toaster is warmer.
I've said it before and I'll say it again. Blocks have no place on a precision, or a tele, or a strat or anything apart from a jazz bass, jazz master or jaguar. Apart from gibsons.