Yes, I would agree about DSA being unlikely on the face of things. However, it also remains to be seen whether Peel will hose down Jet2 with cash to operate routes from there.
In terms of the aircraft, it really is up to PM this time around. His modus operandi up to now has been to take older aircraft and the ex-Gulf 767s would fit in nicely in terms of age amongst the ex-Ansett 737-300s and increasing variety of 757s. However, this strategy is dependent upon the aircraft having the performance to do the job - and I seem to recall that they had to upgrade the engines of some of the 737-300s from 3B1 to 3B2 power to hack Leeds in the first place. I suppose there's no technical reason why you couldn't upgrade the 767 engines for the same reason, but I shudder to think what the cost would be. I would have thought it would be more than enough to put off most airlines looking at those aircraft.