I'm pretty sure it is a 200E. While the engraving may be a little different than those you have seen, the coverage is about the same. Given its date of birth it would not be considered unusual to find a different pattern than those made in the 60's or 70's.
In the next breath, I must say that it is a fantastic gun! I love Merkels, they are so solidly built and yet retain that light and lively feel. The gentle semi - pistol grip stock accommodates the double triggers nicely, and 16 gauge is ideal for an all around hunting gun. I don't have a Merkel (yet) but I came close to buying a SxS at the Calgary gun show last year, and I have handled a couple of 200's. You have to spend a lot of money to get a better gun. The stock wood on yours looks very nice - any chance of a more comprehensive picture?
Great find, Grouser - a great gun in great shape. Good work!
Sharptail