I didn't get into Mak's when they were cheap but, have been collecting them for the past couple of years. Amazingly simple and robust little pistols.
It sounds like you got a good price.
These drop in fixed sights are aluminum but, most reviews are solid. I think they look better than the OEM adjustables.(Check out JeremyWillis' post to see him use one of the sights and parkerize his pistol. Looks like media blasting removed his slide markings as well)
https://www.gunpartswarehouse.com/Makarov-IJ-70-Fixed-Rear-Sight_p_26.html
ETA- I like Pierce grips for shooting comfort but, East German grips are IMHO the best of the surplus variants. Polish Iron makes a cool modern grip that is very comfy and looks good as well.