Ouch.
I'm afraid there's no way around that, Oct.
You could try either:
1) sadly, remove the text and replace it with symbols or a banner-like picture to just represent what was there in real life..
or
2) moving the text into the part of the plane, where it doesn't mirror at all.
When decided to skin the 8//JG52(did u receive it btw?), there were some Bf109G-10s with texts written on it but I had to give up on all of them and choose a 109 that had no trouble using a mirrored fuselage to skin.