is this rear caliper salvageable?

[His Dudeness]

I have in the past (on my own bikes) run a rear brake with no dust seals in but only as a temporary measure. If the main seal is in good condition it is not a problem..... I wouldn't do it on a front brake but on a rear as a stopgap measure its not a problem.

So have I for a couple of days to get back on the road while waiting for new seals but riding around for a year banananananannas