Just got home from the vet's and the news is all good. The vet checked Mickey over inside and out and took x-rays to be sure; there is no hair of any significant amount remaining inside him.
Needless to say, she and I were both thrilled at the results. The big goal now is to get him to eat more hay to keep his system moving normally, but we may not see much action there until after his quarterly tooth grinding at the end of Sept.
As for Mr. Mick, he is currently sitting next to me, stuffing himself silly with dandelion leaves. Either all that tummy prodding certainly stirred up his appetite, or he's figured out that if he wants to avoid a trip to the vet's, he'd better eat. ;)
Thanks so much to everyone for all the well-wishes; it helped more than you could imagine. Hugs to each and every one of you--and a few licks from Mickey, too. :)