Congratulations on your new-to-you EAA Witness and may it serve you well!
Your Pistol is a mid term-production of the series 88 Tanfoglio Pistols and these were very well made Pistols. As you have already determined, the Magnum Research Baby Eagle Magazines are EXACTLY the same Magazine as the Small Frame 9mm Witness Magazines. In the past, when I have ordered Mec-Gar Small Frame Witness Magazines, the packaging often says Baby Eagle/Witness.
Cz75B Magazines can also work, but for the Limited Capacity Magazines you are required to use, I recommend you stick with the Magnum Research Baby Eagle Magazines.
Also, I recommend that you replace your Firing Pin with a new version, if it has not already been done.
I have a slightly earlier Full Size and Compact Series 88 TA90 Pistols that have been, and are, exceptionally accurate.
Technically it’s a TZ75 because of the frame mounted safety. I believe Excam imported the TA90 with mostly slide safety and FIE imported the TZ75 with mostly frame safety. I also have one of the ITM AT84S pistols in the box unfired. Fun fact: that “The Ultra” pistol was imported into the US by FIE but the one I have has no import marks on it. I’m deep in love with Tanfoglio pistols but there are sooo many variations that it is hard to keep them straight. jwc007 is a wealth of knowledge in this area.
In general, you are quite correct!
However, just to make life even more interesting,
towards the end of Excam's existence and it's merger with FIE, which would later become EAA, there were about 400 Tanfoglio Pistols marked TA90 imported that had the Frame Mounted Safety. They are marginally collectible and typically rare.