[Heathkit] Need info on SB-110 vs SB-110A

[pmills7 at houston.rr.com]

I have just received two of these nice six-meter transmitters.  One is 
supposed
to be an "A" model but there is nothing tag-wise to indicate which is which.
Can anyone tell me how to identify which is which?  About the only thing I
notice looking at the top of the chassis is that there are four crystals in 
the upper
left hand quadrant that are positioned differently.

thanks, 73,
Phil
W5BVB