Greg's (user G E) guide is what I used for guidance. I found the detail and the pix he included gave me the confidence to understand what I was getting into and take the plunge.
https://www.audiocircle.com/index.php?topic=137131.msg1458796#msg1458796Yes, just as you stated mounting MDF to cover the holes using caulk and some wood screws is what I did. G E included pics of his covers in his guide.
On the Creative Sound Solutions APR10 passive radiator. The radiator was $65 in 2018 and I see now is $90. As G E states the rubber gasket was slightly too large to fit in our cutout. I used scissors to remove some material to get it to fit. Greg used the 3M Strip Caulk which is great stuff.
Your two spare 10" Misco drivers will be gold to an RM40 owner looking for spares. Selling should pay for most of the upgrade. I sold mine and later I needed a set to spare a pair of RM40's that came into my life. I purchased a pair for what I thought at the time was an obscene price, but now looking back I consider them a bargain as they are made of unobtainiam.
