[1000mp] 1000 MP Serial number and age and problem with thumping when keying c.w.

[Paul F. Sehorne]

I am looking at an FT1000MP Mark V Field.  I understand some of the 
early versions had an issue with thumping keying c.w.  The one I am 
looking at is serial number 2h070698.  How can I tell if it is one 
afflicted with this problem?  or at least determine its age?

Thanks,
Paul, WI5F