If your hens are free-ranging and you picked up a box and they ignored worms, that means they are getting enough protein, so you really don't need the bugs unless things freeze over. If things freeze over where you are. If you are worried about them getting enough, you can place some boards or cardboard or some veg material (straw, hay, garden waste, etc) in a low layer....not compost deep, or it will heat up too much for worms....and rake it aside now and then to pick up worms for them.
I'd store the mealy worms right in the freezer for them.
How I get pumpkin seeds: I glean pumpkins (with permission) from a farm or two that sells pumpkins for decorating. The day after Halloween, I can take the pumpkins. If you don't want hundreds of pumpkins like I do, you can go into the field with a machete and a bucket and gut the pumpkins right in the field, if they will be plowing them under.
I don't know if you can buy them raw in bulk in a form that will sprout....at least not for a reasonable price.
There is a house near me that has a carved pumpkin display every year that is hundreds of pumpkins, and each year I plan on stopping and asking if I can have the guts, each year I forget, then I can't remember which house it was to ask beforehand! Maybe next year....
If your flock free ranges every day, then what you feed them is really a supplement to that, and the mix is not critical. So your homemade scratch mix looks great! It has more variety than what I feed my flock (I don't feed any commercial mix at all.)