Their silencers were t same as the old fmf ones. had one on my 250 for years. never tried the pipe but i would guess it's probably pretty much the same as running an fmf or a paul turner. Not a whole lot of difference in pipes back then.
If it's a 250 QR pipe it's a fmf copy, paul turner/duncan pipes are different. I believe graydon was a sub co. of FMF.