I read on another internet site that the last run of all german manufactured
Assembled and proof marked 228R pistols were sold in the 2011 time frame and
had matching serial numbers marked on the frame, slide and receiver. Also
read that only 200 were made.

Is this true and is there a published source of this information. Thank you

Neither SIG nor SIG Sauer have published such statements. Nor can any such information be found in reputable publications after 2011. It may be that a dealer has received such a confirmation, but without it, the statement on the "internet" is worthless.

I doubt it was only 200 made. Only 200 imported (by Exeter NH) is more believable. Of course, I have no idea as to production numbers for such things, but I have noticed that some of the rarer configurations of SIG Sauer pistols, such as plain-Jane models made and proofed in Germany in the early 2000s or later (which is the category the P228R would fall into), are really just rare in the USA, not globally. This was simply because demand for such models was generally fulfilled by the USA-produced and/or USA-assembled SIG Sauer pistols.

What OTD said.