Most of the Rottweil guns were made by Fratelli Gamba, although apparently some of the early field guns were made by Zabala Hrms in Eibar, Spain. Frli Gamba made good guns and some of the trap guns were very good indeed. 28" barrels choked IC/M sounds like a field gun, but the removable trigger group throws a wrench in the works. That design seems to have been made at the very end of the Gamba Bros arrangement in 1990 and thereafter by Renato Gamba who continued production of the Model 88 (with removable triggers). Guido Gamba seems to have maintained ownership of the Fratelli Gamba name for some time but does not appear to have continued producing guns. It does not appear that Renato maintained the relationship with Rottweil, so maybe this is a 1988 - 1990 production Model 88? Renato Gamba apparently changed the Model 88 design and it became the Daytona.
Anyway, there are allegedly still parts available for the Gamba made Rottweil. I think I would want to verify that. A gentleman named Chris Vendel allegedly still provides Rottweil parts - at least for the Montreal and 72 models. Nothing turns up for the 88.
Anyway, that sounds like a nice field gun. I think I would like to be sure about model and parts availability before spending but if the gun is in good condition, that seems a reasonable price.