I finished the main quest (Vampire side) and the Priest is giving me no options to get rid of the elder scrolls. 60 pounds lost.

That's because you chose the Vampire side, he is your thrall now and is under your control. If you had chosen the Dawnguard side you do not make him your thrall and you will get the option upon completion of the questline to give the elder scrolls to the Moth Priest.

60 lbs not lost

quest items have a weight in their description but they do not actually count toward your encumbrance limit.

the number you have right now is the same as if you didn't have them.

In other news, he took the scrolls fine for me (dawnguard side)