I'm still on my quest to find a tactical holster for my USP .45 tactical.  Digging through Safariland's "will fit" charts, the 6004/6005 list a "96" variant that fits the "USP40 Expert, USP45 Expert" with a bbl of "5.20".  The tactical has a bbl of 5.09", so in theory if the frame is the same it should be compatible (in theory).

When I called, they could not confirm so I'd have to buy one and see if it fit - I'm doubtful of finding a specific model at any local retailers.

Anyone know how closely these two are in shape and design?

From memory, I don't think the 6004 uses the frame for retention, I think the slide/barrel play a part in the retention as it sits in the holster.  The rear hood slides over the rear, the sides of the holster hold it tight, and the gun rests on the forward shoulders of the slide/barrel... ****I think****

But yes, the Expert 45 frame is identical to other USP 45 variants, assuming the ambi control levers don't get in the way of anything (I think it's got ambi levers...)

Expert is ambi-safety and match trigger assembly with stop.
Frame is the same.

All USP .45s use the same frame.  All USP 9mm and 40s use the same frame but different than the .45 frame. Same for the compacts, 9 and 40 the same and the 45 is different.

Full size USP 45 have the same frame for Elite, Expert, Tactical, Match & full size. Which I happen to have all. The main difference is the length of the slide on each. Same mags, different recoil springs. Hope this help.