Beyond my skills, but could a competent gunsmith fit a Model 10 4" heavy barrel to a Model 15 frame (or 64 to 67) and create a knockoff of one of the Dayton guns?
Probably would need a different rear sight blade, but that would be minor.

I doubt the front sight on a Model 10 barrel would be high enough to work with the adjustable rear sight on a Model 15. Not sure a new rear sight blade would be enough to make up for the difference.

Steve

Message sent re Dayton BBL.
GAF

stay tuned....12 weeks?

my Model 15 is at Bob Jones Gunsmithing

and I found a 4" heavy barrel with a Model 15 style front sight that took a ride with the gun.

I actually bought a Model 10 HB that Bob Jones said he could put a front sight on that would work, but I wanted my gun to be legal for NRA Svc Match and he said doing that with the model 10 barrel would not be legal since he would be using non S/W parts to complete the project.

now a I have a Model 10 H/B laying around.

..............................

much to my disappointment, I got a phone call from Bob Jones today. He said the barrel I sent was from a Model 10 and it would not be legal for NRA Service Matches. sniff..sniff

my search continues for a Model 15 heavy barrel.