Here is a link to the gnb fish stocking info. You can look through and see what lakes were stocked in the past few years, as well as the number of fish and their size at the time of stocking. I didn't notice the Minto mines, but I just took a quick look.
I haven't heard any positive reports on those old mining ponds in years and am fairly sure there's little if any stocking. Last time the guys and I tried them we got skunked, not even any too small to keep, but that was a few years ago. I don't think they get much fishing pressure any more so you never know what you might find. I'd check to be sure they're still open for ice fishing.