The regulator you should get is the Wells VR15. I haven't looked to see who carries them but I know that they have them here: https://www.theregulators.com/wells-vr715-voltage-regulator/

Other than finding used stuff if you can, Dale's Muscle Car Parts is a vendor in Bracebridge, Ontario that carries some reproduction Beaumont parts. http://dalesmusclecarparts.com/

I seem to recall that NOS Reproductions was doing Beaumont upholstery but it does not appear to be the case now.  SOmebody asked that question 10 years ago at this site: http://canadianponcho.activeboard.com/t15878172/65-acadian-beaumont-interior/