[Magnum Wheel Man]

Just a budding hobby holster maker myself... but if as you say, it's "old" is that 2 years, 10 years, 20 years ??? if the leather is drying out...

anyway I use Feibings 4 in one for molding my holsters... it's a conditioner, & I'll apply it heavily to both sides of the leather, a couple of times, really soaking the leather through... sure, do the belt too... but do it before a long range session where you'll be wearing the belt, & the gun will be in the holster as much as possible... while in use the holster & belt will dry out & be re-form fitted for you & your gun... adding something like Dr. Jackons leather conditioner afterwards will help keep it from drying out again, without causing it to go all soft & limp...

my expirience here, is that when "wet" the belt loops ( which I like tight on my carry rigs ) & the holster body, stretch out to best fit, & if allowed to dry out leaves a harder molded shape that fits the curve of my waist, shape & thickness of my belt, & gun, & the holsters retain that shape well...