HP-15C Enter key issue (s/n: 2241A)

[jebem]

I have acquired another classic calculator, this immortal HP-15C.
I'm very excited to finally have one of these samples in my hands to play with!
The calculator is in very good condition and works nicely.

However this beauty has a dark side, and I wonder if one of our expert fellows can help me on this one:

1) The ENTER key is kind of sticky and seems to be on the loose side (it rocks sideways), despite it never fails to register.
- Is this kind of issue happening on a regular basis on old calculators like this one (year of 82)?
- Can it be fixed?

2) Also, I notice that the key only clicks in the upper side, and the lower side has less height that the upper side (please check the pictures for details).
- Now, could someone confirm that on a perfect ENTER key this is normal, please?

Thanks in advance!

Pictures: