Howdy!
If I may suggest;
Don't make a permanent loading jag
or affix the arbor permanently. Leaving he magnet system is no problem. Perhaps the arbor could screw in place. This way, when a Remington shooter who buys a Rem. Loader, THEN LATER buys a Colt, you can sell an upgrade "kit" that comes with the other jags and the larger arbor - that also screws in.
Just like Dillon has done with their RL450 Upgrade as well as the upgrade system (a set of 4 assemblies, purchased separately) to make their AT 500 loader into a full-blown RL550B.
What would be the difference between a regular version and a Rem ONLY version?
Sell the Rem set for $59.95 (or whatever) and sell the Colt arbor and the 2 or 3 magnetic jags for, say $29.95. You've added 3 threading operations to the original loader ... and as a
machiner er, ... machinist,
I'm sure you know how simple threading 2 sizes of rods and a hole CAN be.
Then announce to the world the availability of "The "Triple 'P' Upgrade Kit"
Just an idea ... from a prospective shopper.