While the injectors were out if it were me, I would take some marvel mystery oil and pour it right down to the cylinders and let it sit overnight. Not a lot, don't wanna hydro lock things, but since the motor has been sitting idle for a while you want to make sure all the rings are nice and slimy. This will ensure that, A, you have good compresssion, and B, that things are properly lubricated from having set for a prolonged period of time.
Also, if the WD doesn't loosen things enough, try AeroKroil. WD isn't really a hardcore penetrant, but Kroil is. Orange colored spray can. You won't find it in the auto stores because its not a "value" brand and will probably have to get from an industrial supply place, but very worth it.