The 40-690 listed is identical to the one I use except I have the stand and light in storage building. I have no problems with the saw except the brief periods of maintenance takes me away from cutting. If it was not so far to travel, I would make it two 40-690s in the shop.
The 40-690 is as Kevin states, is a grey 788. So identical that the part numbers are the same as the 788 (except for the decals). I have looked at parts list at Delta, Dewalt, ereplacements and others. So I firmly state that as long as parts are available for the Dewalt 788, parts for the Delta 40-690 will be available.
Larry