As always with Meopta, the answer is at http://www.meopta.cz/ . The site is recently reworked, it seems, but older enlargers are under "history".

Lens boards are relatively easy to find here, in both 23.5 and 39mm. Same for lenses, and the Meopta Anaret-S lenses are surprisingly good! My Opemus 6 can take Durst flat lensboards without difficulty.

I think the Meochrom head had only one mixing chamber. The later Color 3 head has different mixing chambers - I have both sizes, so just check that the opening is more than 4cm across and you should be fine for MF.