HD 1206 Brake Drum - Dexter?

I have a call into Dexter, but I thought I would try on here too. My brake drum is marked HD 1206. Is that a Dexter #? It has an "R" inside an oval on the drum too. Perhaps on Al Ko (their website isn't too good). I am thinking about switching to self adjusters at some point and I am trying to zero in on the parts.



When I install new backing plates, is it a good idea to install new drums/hubs? Mine do have some magnet scoring. Note, I also posted on here today about magnet/bearing wear.



Thanks,