[Elecraft] New User with some questions

[gmuller885]

Hello all:
     I am the proud owner of a slightly used K-3 and P-3. The serial numbers are K3=SR# 3227 and the P3=SE#853.  First of all can any one tell me when these were made and how do I find out when they were purchased? Second how well does the automatic Antenna Tuner wor?. Third, I have a Heil Proset Elite head set. Where do I get the adapter for the head set to the K-3?  And last but probably not least what is a very good desk stand mike, not a hand held? Any and all legitimate help would be appreciated. 

Jerry Muller  KF5EYC 
GMuller885 at aol.com