Seatbelts---reuse or new?

So I am working on getting the 72 fish running ...but one thing I know I will need to do is get the seatbelts back into the car...they were removed when the car was painted and cleaned out, etc......

I have a set of belts for the back and the two receptacles for the front....but dont have the retractor belts for the front.....What I have is pretty dirty and grungy.....will need cleaned at the minimum...possibly dyed.....

SO questions arise here of course....I dont want to use anything to clean them that will degrade the belts....so planning on maybe one of those orange cleaners for that.....

Or am I better off getting new belts, safety wise?

What do you guys do?