I'm also in the process of making a roller cam core, using two pieces of solid round steel stock, press-fitted onto a distributor gear salvaged from a worn out stovebolt cam. I'll make a round shank about 1" in diameter on both sides of the gear, bore the end pieces a little bit undersize, then press fit and taper-pin the assembly together. Once that's done, bearing journals and lobe blanks can be machined on my lathe for the cam grinder to finish up.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!