Yours should be a box lock, case hardened receiver with scroll engraving. It should be a double trigger gun...does yours have an articulated front trigger like the sidelock?

They are an excellent gun. I believe the importation of this gun into the US was discontinued in the mid or late 1990's. Merkel has made them, or a variation for many years. Your box lock would most probably take more hard shooting than my sidelock.

I like sidelocks for the simple reason that they have more room to scratch up the receiver with some nice engraving,

but would tend to trust your model more, over the long haul...