Yup, you're right Mike. I loved my T5 so much that I bought a PT4 (from Old Horse Murphy, unless my memory is failing me). Precision-shaped body (= P), but fitted with a pair of Lull's own Thunderbird pickups (= T), and it's a 4-string (= 4).
I own more Precisions than is right for a grown man, including two all-original vintage Ps and two other Mike Lull Ps fitted with Lull's own Precision pickups. The PT4 is (IMHO) both the best sounding and also, due to having two pickups, potentially the most versatile.
I say 'potentially' because I'm an all-knobs-to-max-and-leave-them-alone kind of guy so I don't do much actual, y'know, testing of these things.
Tonally, the T-pickups take the PT4 into Seymour Duncan Quarter-Pounder territory ... like a Precision, only more so.