Sig 220 with no date code

[VHinch]

I have a two tone Sig 220 that I can't seem to find any manufacture date information on it, as there is no date code on the pistol like there typically is on Sigs. The slide is also stamped "Made in Germany" rather than "Made in W. Germany". I seem to remember seeing a reference to this run of Sigs somewhere once upon a time, but I can't locate it now. Anyone have any insight here?

Thanks
V