[Heathkit] SB-300 versus SB-301 differences

[jack m]

Hi group,
 
I want to replace a bubba-damaged RF Osc board in my SB-301 due to a previous socket replacement attempt gone ugly.  Currently, there is a used board in nice condition up on EBay for an SB-300.  The board number is given as 85-72F947 as silkscreened on the top.  I give everyone permission to search for this, but NOT permission to buy it out from under me yet, of course!
 
I do not have a schematic of the SB-300 or x-ray page for comparison with my '301 manual.  Further research shows that these appear identical physically, from the top, but no underside trace photo is available for a tedious comparison.  The part number silkscreened on the SB-301 is simply 85-72.  Knowing the obvious upgrades for the '301, my gut feel is that the boards are the same, but I'd like other opinions.  Before I buy it, Is anyone aware of a difference in applicable circuitry between these two models?
 
Would anyone have a later '301 osc board in nice condx from a parts rig available for sale?
 
Thanks
 
Jack