Most importantly, I hope your eye is coming along without any problems. If you're having issues with it, it can be a real time bandit. We're all hoping its coming along with no problems.
With regard to your sled mods, have you been able to do any further work on it? I'm intrigued by your dual retractable fins. That sounds really sweet. If you have it by the Winter hang, expect a lot of us to be drooling over it. I've seen many a pulk in my day, used for ice fishing mostly, but none so sophisticated as to have retractable fins.
My first sled didn't even have fins, and when I hiked with it, it was all over the place on anything but flat terrain. With the addition of fins, it took the sway out of it on inclines, but every so often got hung up on underbrush or other trail debris. (My poor fin design). With retractable finds, no worries on getting hung up.
All the best and hope to see you at the Nor'Easter in January.