Thanks for the update. I also did contact them by phone, but the language barrier is there and I couldn't understand much from the person I was talking to - conversation lasted about 2 1/2 minutes.
From what I could gather they told me to look at the website - but the website isn't working correctly (certificate error of some sort or it's hacked, something along those lines). I do know that when you look at their website they copied/pasted their product description from the Matebafan website for the .357 info, so you get all calibers and barrel lengths being offered (minus 5", though it was offered in the past so I'm assuming Matebafan missed this). For the .44 mag main description, it states barrel lengths from 5 - 8". I will assume that the .357 will also have a 5" barrel option, since it wouldn't make much sense if it didn't.
Under the parts category for revolvers there is nothing listed but the picatinny mounts - and that is a big problem if true. However, even at the recent IWA when Mateba was there, we can clearly see they had compensators on at least one 6 Unica, so I would assume spare & accessory parts can be purchased, they just don't have them listed.
I can also say I'm far more concerned with spare & additional parts than any warranty work. Since this company stopped producing these guns for almost 20 years, and if this is a limited time event, I can't see them hoarding any parts for future issues. Springs, grips, compensators, barrels & shrouds (edit: and cylinders) - these are the main items & prices I need to know. Any other extra stuff you can coax out of them, great.
I also don't know if they said they're making .454 versions or not.. I heard yes and no lol.