Carter, which mouthpiece are you using now? Is it the same one you used before? Have you been playing since you stopped using the 72*, or did you stop for a while and resume playing recently? Are you hearing your trumpet in the same space/surroundings as before? Are you playing it the same way as you used to? Are there problems with your technique of which you are not aware?
The 72* has a brighter sound than a standard weight 72, plus it sounds darker behind the horn than it does in front of it. The 72* is a very versatile, flexible horn; you can create a variety of sounds, from full and dark to sizzling. If I wanted a less "thin" sound, I'd try a slightly deeper mouthpiece, BUT this would be after I exhausted all other possibilities. A different mouthpiece at the entrance to the trumpet will not solve problems, weaknesses, techniques, nor deficiencies behind the horn.
FWIW - When I first had my 72*, I was using a Bach 5C, and my teacher at the time and I tried to get me to overcome a difficulty I was having with attacks; I never could get them clean enough. I must have spent over a year and a half trying to get my attacks perfect. At the time, I kept hearing that many players were getting good results with a 3C and its variants, so I tried one... problem solved instantly and permanently! It obviously fit my embouchure better than the 5C did. YMMV.