Sheap. I would re-centre the mount on the tube & then centre the finder in the mount.
Take your telescope outside in the daytime, (do not look at sun or leave unattended).
Find a fixed object, like the top of a tower or pole at least 500 to 1000 mtrs away. Using your largest E/Pc, eg; 20 mm ??, line up your t'scope on that object.
Now adjust the finder onto the SAME object. Switch to a smaller E/Pc & redo the collimation.
As for condensation, well do not wipe the mirror or touch it at all. Use a hair dryer, either 240 volt or buy a 12 volt one if going to a dark site.
This can be used to keep your E/Pcs dry, till you either make or buy an E/Pc box or case.
HTH...
L.