Thanks to all for these ideas!
I suspected it would work, or some similar technique, but since I haven't purchased a swivel knife yet, I thought I'd throw it out there to the experts.
Tree: I actually made a freehand groove cutter after I left my local Tandy store (45-50 miles) and forgot to purchase. It actually works superior to my purchased groover, and I have since made a a new cutter for the one I bought ( out of an annealed allen wrench) which also works better than the store bought model. I really dislike the locking mechanism they have, as it is unreliable, and comes loose quite easily. I've scratched out a new design to fix that, too. I sure wish I had access to a machine shop once more.
Pabloz: I suspect that the stylus trick ends up looking cleaner, like a machined stitch? Care to share a photo?
Thanks again, all.
Jake