This is a project in progress. I have found a drop in replacement woofer for the minimus 7. This is a 4'' Aluminum Cone Woofer
from MCM Electronics. It has a much larger magnet than the original Minimus woofer so you have to align it just right to squeeze it in there but once in it screws down with the original holes. It's a much lower distortion woofer than the original so if you just replace the original with this and a series 1 mH inductor it is an improvement. I do plan to work up a better crossover and also replace the tweeters so once that's completed I'll update this project.