Successfully replaced the Icemaker with Part Number AP3182733. Everything worked fine from the get-go, ice reservoir was replenished over a couple of days, then, over the next several days began to notice the ice supply in the reservoir was dwindling.
Put my hand in the icemaker to see if there were cubes ready to fire, there were, but it was clear that the ice level was high, as if the water went into the tray once, froze up, and then water went in once again.
Pulled the unit out, let it defrost, put it back in, worked perfectly again but ended in the same result with a double-dose of water filling into the ice tray.
Pulling, defrosting and putting the unit back in seems futile at this point, looking for a revised repair path.