Exel Arms double barrel shotgun

I aquired a Spanish made double bbl. shotgun I'd like some information on. It's an Exel Arms mod. 221, made by Ugartachea in Spain. It has 28" barrels, straight grip stock, color case hardened boxlock receiver, with double triggers and extractors.
The gun is in 99% condition.
The blue book lists the 200 series and says 213 is the highest grade. Does anyone have any information or know where I can find anything on the mod. 221?
It's a great gun, but frustrating since I can find no info.
Any help would be greatly appreciated.