You know, I have a couple of those I am not using any more, and I would sell one for less than $75. It would include the mounting bracket and transformer attached.
Send me an email and we can discuss it more.
DavidSousa@verizon.net
The way that these are mounted on the reed blocks involve making a bracket with stiff wire which wraps around the mic and then gets screwed onto a reed block. Take a look at the website in Link #1 and you will see pictures of two different mic mounting systems in a Cajun accordion. Big Nick was switching from having it mounted in the usual way to an improved way. The first couple of pictures show how it started out, which is a commonly used way to do it.
alternate approach
i have 2 cheap mic elements [took the mics apart]
dynamic
in parallel
they are $5 karaoke mics originally
they point directly at treble reeds
nothing needed to pick bass up
they are attached to the treble block via a coathanger wire assembly
there is very little room for mics where they really need to be
because the bass side will hit them when the bellows are closed
mine has about 2mm to spare or less