Jeff
In five weeks time everybody here will be sizzling waiting for your pictures.
I think that getting an all matching (I assume) HK with two matching mags is a very big score on your part and surely it's a big way to start a collection; because, I assume that you haven't bought a HK to take it down to the range, have you?
If I were you the only thing I would do now would be field strip it (mind the grips, but you already know that) gently clean it and lube it with some BALLISTOL.
As soon as you'll get more expert about it, you'll have to disassemble it and check every part for rust, clean & lube it, then reassemble everything.
Congrats again!
Looking forward to see your HK.
Best regards.