SA2 to BSD caliper upgrade

I own a 2014 Kosmic Mercury which has (what I believe to be) an SA2 caliper installed.
I’ve been having problems with brake pressure as my master cylinder has quite a bit of corrosion and I think that there’s air getting in somewhere as well.

I’ve decided that instead of repairing what I’ve got it would probably just be better to upgrade and buy a BSD brake set second hand as it would end up being better value for money.

Just wanted to know if the SA2 mount I have would fit the BSD caliper and whether I would need a spacer at all? I run a 206x16mm brake disc for reference.