It's not necroposting if the last post was 4 days ago, right?
To clarify my experience the recoil tube from the other thread... There is no overt reason you couldn't reuse the original recoil tube with the Sulun one from Delta Mike's. They are identical, which just confirms my initial suspicion that the 601 DPS is pretty much the original Sulun Tac-12.
I thought I had damaged or the hex nut was stuck when I removed the assembly from my 601 DPS and it came off in one piece. After I had everything apart, I hit the hex nut with another minute on the torch and the green loctite finally gave up and I could take the hex nut off.
Reusing the original recoil tube is just a waste of time and effort. The new Sulun assembly includes everything and you just need to screw it down, tighten the hex nut, and spin the grip into position. To transplant it to the old tube, you'd need to spin the hex nut off on both tubes, spin the grip off of the new one, spin it on the old one, put the hex nut back on the old tube, then pop the stock off the new tube and onto the old one. Absolutely no reason to do all that. Nothing magic about the old tube. I kept it as a spare part.