Problems? Lots of them. These were most definitely an experiment, and some parts were more successful than others. I think I could do a much better job the next time.
For one, I forgot to remove the heel tack before removing the left shoe from the last, and tore out the decorative punchwork and stitching on the counter:
Also, the top edge of the counter isn't tall enough - when I wear the shoes, they feel like they're about to slip off my heels. On the other hand, too bitey of a top line along my achilles' tendon on commercially produced shoes has long been a problem for me, so I think I just need to remember to start lasting with the heel point up a little higher on the last.
My lasting wasn't great, so the pattern is a little distorted. It's hard to tell, but they're just a tiny bit lopsided. I notice it, but I doubt anyone else ever will.
Here's the last two problems: The beautiful back line I was going for completely disappeared. I think I may need (eventually) to invest in a splitter. I've been using suede and hirschkleber for my counters, and I think they're just not robust enough.
Second, the oak heels, which I thought I had sanded smooth enough turned out to be not smooth enough. I can see the uneven ridges through the kangaroo leather, which seems to magnify the problems, rather than leveling them out. Next time around, I'll be experimenting with casting heels from plastic, from Smooth-on, and inserting one or more steel pins through the center.