[Edward Tinker]

Paul, welcome

I made it so you'll get notified if someone posts.
As usual, pictures help a lot. The suffix is part of the serial number.

Taking a Luger down is easy, once you've done it ten times. I never tear down past the cleaning phase, I.e. Less is better in my book.

Biggest trick is ensuring you don't force the takedown lever, release the tension first by pushing barrel back on a hard surface, your hand, etc.

Welcome to the forum!