We weren't as ambitious as you were, partly because we don't have a Bimini so no need for the enclosure.
However, my wife sewed up a front window cover and side curtain/sun screens out of Sunbrella.
Next on the list is a removeable side curtain for the back deck so we can sit out there when the sun makes the back deck too hot, and blows into the big back window baking the saloon..
We were lucky and in the family was an old '50's Singer that was, although not industrial, not too far off as my Mother used it for professional sewing many years ago[I was a twerp,maybe still am]. It won't do fancy stitching without a lot of attachments and which would be useless in this case. It didn't really like the heavy stuff but there were only a few spots that required more than three or four layers. A thorough oiling and greasing before hand, new belt, new needles and it worked well.
If you aren't too ambitious and expect to only do lighter stuff and not a lot of it then one of these may be suitable, particularily if the price is right.