Cowdog - I do not know the answer to your question. Is the deck that you found an RC60-24B or an RC
K60-24B?
I have a 2003 B7500 HSD-R with the RCK60-24B MMM. My operator's Manual shows the RCK60-24B, RCK54-24B & RCK54-75B decks used with the following tractors: B7500, B7400, B7300, B2410, B2400, B2100, B1700. The installation instructions for both the RCK60-24B & RCK54-24B decks are the same in my manual. I found no reference for using a different part for installation of one or the other, however, this manual does not show part numbers.
If the deck you found is the RC
K60-24B, I suggest that you go to
www.TractorSmart.com and request free downloadable PDF parts lists for both decks. TractorSmart will email the links for the downloads to you. Compare the part numbers for the brackets and other mounting parts. If they all match, you should be good to go!
If the deck you found is a RC60-24B, you might still request the parts list, and compare both parts and part numbers.
I don't know how age of the equipment might impact the comparison. What did you mean when you called the deck you found "older"?
Best wishes!