I knew 6510. There was ...I think an accumulator, an x and a y variable, and that stack thing sounds familiar. Not sure about local though. It's been a long time.
I might start coding the "right" way for future projects after I read up more and convince myself that it's better, but I have a marketable product as it is. It's essentially complete and I could deal with whatever issues come up (and I'll be putting this to the test soon because I found a couple of bugs in one of the oldest parts), but don't worry...you're all doing a good job making me feel like I did something wrong.