MicroVax batteries

The batteries in my MicroVaxen need to be replaced. A couple of questions: What's the best way to clean up corrosion damage caused by these batteries? With Alkaline batteries, I usually use vinegar (since alkalines leak a base, not acid). What about NI-CD? What types of batteries can these be replaced with? I'm assuming that this is a NI-CD battery pack. I went to Radio Shack expecting to simply find a cordless phone battery that I could use to replace it - the pack appears to be nothing more than three AAA NI-CD cells in series. Unfortunately, the only sort of phone batteries they carry are either too big (AA's) or NIMH. I wouldn't imagine that it would work, but is it possible to use NIMH batteries to replace the original pack? I ended up buying a small pack at Target, it's a small, three cell (half or third AA, it appears), phone battery pack. NI-CD, 400mAh. But, you know, I'd like to know what my options are for the other MicroVaxen... Thanks! -Ian