[Elecraft] List of Popular K2 User Modifications?

[Mark RAYBOULD]

Having just completed my K2 and only recently been following the 
Reflector for K2 topics, I wondered if there was a popular list of user 
modifications which can be added to a K2 apart from Elecraft's standard 
boards.  I hear about a screen for the crystal filters, for example.  
Any advice is appreciated and thank you all in anticipation.  (On-list 
or Off-list)

72, Mark Raybould
G3XYS
KX1, K1, K2