Taken from the Abercrombie & Fitch ledger for GH Ejector guns, page 355, one can see a Mr. E.F. Hutton purchased a 28" barreled 20gauge GHE on October 23rd, 1934. I believe he was a somewhat prominent banker. I doubt the value of two equal condition GHEs made 10 years apart would vary at all in 1960.

DH $85 to $125; CH $175 to $250

From the 1955 Abercrombie & Fitch used gun list FALL 1955.
DHE 16 ga 28" barrel good condition $250.00.
DHE 16 32" barrels Single trigger Excellent condition, $400.00
BHE 12 ga 26" barrels,good condition. $400.00.
Hope this helps

I remember being in the Abercrombie and Fitch showroom in 1960. I was sent a used gun list by mail shortly after. I still have it, addressed to me. Two AAH Parkers were there in the gun room at the time and were also listed in the used gun list. One was $600, the other was $650. They were tired guns, but well worth the asking price, even in 1960.

Not to prolong this, but according to my source:

"$650 dollars in 1960 had the same buying power as $5406.49 current dollars."