When I first visited Madras, the Erickson firefighting fleet was in the process of transitioning from the DC-7 to the MD-80. That transition is now complete and the DC-7s are now all stored with some of them on the ramp at Madras, gently baking in the sun. The conversion of the MD-80s has been underway for a while. A bunch of ex Spanair jets were there last time I visited. On this visit, there were a few MD-80s out on the ramp that appear to be providing a source of spares for the in service aircraft.
I don’t know whether these jets will eventually get modified but, given how much has been taken from them, I suspect not. Various control surfaces have been taken and panels removed. I have no idea what the systems inside are like but I would imagine that those are the most valuable parts. However, any spares are worth having since the MD-80 fleet worldwide is dwindling and supporting the air tanker fleet for a long life is going to need a good stockpile of parts. The dry Madras atmosphere makes for a good storage environment so the planes should be in good condition for a while yet.