OK, I went out and practiced landings this afternoon, a fairly gusty, crosswindy day. I think I've figured it out.
My theory is that because the STOL wing still wants to fly at lower speeds than the stock wing, the airplane is more sensitive to pitch changes during landing. When I set it up on final in more or less the wheel-landing attitude and use a little power to control the descent rate and take care to minimize the pitch changes just before touchdown, I can get a very nice, controlled wheel landing. If I get a gust and overreact to it, the airplane will balloon, bounce, porpoise, etc., and my friends, who like to sit outside their hangars and watch the action, get very amused at my expense!
My friend with a stock '53 170B was out there practicing landings at the same time, because after flying mine he wasn't sure he could fly one any more. He was making very nice landings, both 3-point and wheel. He feels better now, but he says I can keep my 170 -- he doesn't want it any more.
Thanks for all the good advice, guys!
John