I only saved you $20 IF IT WORKS...
If it doesn't, contact me by private mail (click on my name at left), and I'll swap (a factory 9mm mag) with you for it.
That .40 mag, if you adjust the feedlips, is a semi-hicap. It should hold 13-14 rounds of 9mm ammo.
That said, the 9mm mag and the .40 mag sell for about the same price, so paying $20 Plus a 9mm mag is not a great deal. I saw some factory .40 mags for $25 at a gun show this weekend, and any quality 9mm after-market mag should work in the 85.
(I have an 85 Combat, a 75 pre-B, a 75 Compact, a 75B SA, and some clones. The only one that has problems with mags is the pre-B, which will use "factory" mags only.)