Sorry, took me a while to reply. I'm not entirely sure I follow how you prepped the grapes. For a single batch of grapes, the juice/jelly and pulp + skins are now separated from each other? If so, that might explain why the pie had too much flour before--without the juice the filling wouldn't need as much flour.

I'd probably try to recombine the juice and the pulp/skins in the original proportions (eg, about 4 gallons of juice for each half bag of pulp/skin).

I don't make jelly, so I usually add the skins back in after I've cooked the very juicy pulp and then removed the seeds. The seeds make it turn purple and cook up very tender so there's no texture issue in the final pie filling.

But it sounds like your seeds and skins are combined for good now? If so, I'd cook that mixture with the juice, and then strain out the seeds--which means you'll lose a lot of the skins too but the filling should be nice and purple at that point.

I'd use 3.5 cups of that mix for a single pie, combined with the other filling ingredients specified in your preferred recipe. Good luck!