Need some help with brake issue

The left rear wheel cylinder has a drop of brake fluid hanging on the bottom of one of the seals and looks like theres some residue in that area. I think im going to replace the wheel cylinders, shoes, hardware and then rebleed the rears and see what happens.
I would
for diagnoses,
just remove the junk and C-clamp the pistons into the bores; you can fix all that after you get the hydraulics back.
In that way you only make one trip to the parts store.