Hi, I removed the valve cartridge from my mother's older moen shower valve. It most closely resembles the 1225. I hope to find a replacement today. Two questions: are the 1200 and 1225 interchangeable? Also, while I have the cartridge out, is there any way I should give the inside of the valve body a good cleaning? (light sanding? or just get a rag in there and clean it out?). Thanks for any tips!