Since there's a Carlo Lamberti LV20, it might be that, if that "XX" is treated as Roman numerals. When you take the pictures, try to get a couple of good shots of the label inside. That should make it fairly easy to identify (to an expert like Pierre).
I used LVXX as an example for the new code numbers. Inside it only reads AV800. My guess is that would be what they call LV12, but it just based on the fact that AV1000 used to be the one that costed 1000 dollars and the LV12 costed 800 in 2002 (using internet wayback machine)
How about some pictures? I might recognize it.
I took some pictures.
I was not able to get a clear picture of the label, but inside reads
Shar Model AV:800, Serial: VCT0006A (maybe)
Seeing the "Shar" hint in the label I found this https://www.sharmusic.com/Inst.....4-size.axd
at the Shar music web site.
hope this helps.
Bob in Lone Oak, TX
Bob in Lone Oak, Texas