You are correct that it is based on the Navy frame. The entire water table has been lowered to accommodate the larger non-rebated .44 cylinder, shown below compared to a Navy .36 cylinder.
View attachment 66497
What is the date code (and SN) of your revolver? If it is BS/2002 (when Pietta went to CNC machining) or newer, any CNC Pietta 1860 Army 3-piece grip assembly will work. You may even be able to use the Dance mainspring.
Pietta started manufacturing the Dance in 1996 (BH) as a consignment revolver initiated by Tony Gajewsky. The first ones were .36 caliber. After a contractual disagreement Pietta produced the .44 cal. with 7-1/2" barrels and REBATED CYLINDERS starting with serial # C00128. This production was modified to the current STRAIGHT CYLINDERS and 8" barrel at around serial # C00233. There were only 105 Dance revolvers in .44 cal. made with rebated cylinders.
Any Dance revolvers manufactured from BH/1996 to BP/2001 are NOT CNC machined, and therefore all bets are off that an 1860 Army gripframe assembly will work without fitting.
Just to show off, my Pietta Dance Firearms Co. - Angleton Texas SN C00013, one of only 35 produced before the contractual dispute.
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I had been looking for a Dance .36 for a few years and was just about to sacrifice a Pietta Leech & Rigdon (milling off the recoil shields) when I found this and several others of both calibers (.36 and .44) for sale when Dr. Jim L. Davis (RPRCA) died in 2019 and most, if not all, of his collection was sold to October Country (Idaho).
In early 2020 I posted a thread about his (and other) Dance revolvers, both Pietta (1996) and Uberti (1985) and what history I have found about them. If interested:
Replica 1862 J.H. Dance And Brothers .36 and .44 Revolver (Pietta and Uberti) (blackpowdersmoke.com)
Good luck in your endeavors!
Regards,
Jim