Looks like any squash pollen will do

My squash started out producing mostly male flowers now they have almost all females. Over the last few weeks I have been moving pollen around from Tromboncino, summer squash, zucchini, and spaghetti squash. If the cucumber flowers were bigger I would try them. On days when there are male and female flowers I let the bees do the jobs. If a person wanted to you could easily come up with a bunch of different hybrids.