They stopped hand punching the MM in 1989/90 so its impossible for it to be a RMP you are most likely seeing a form of nav doubling.
Yes worthless doubling you still got 10 cents there buy an ice cream at the truck wait I forgot it's not 1989/90 man time flys by
Not re-punched. Look up on Variety Vista: ...Watershed Dates in the Modern Minting Process. The last possible RPM for dimes was 1990...the last known RPM for dimes was a 1988-D...Spark