225 Engine Rusted Where Waterpump Mounts, Still Leaks After Replacing, What To Do?

My 225 has been leaking fluid like crazy so I took it in to a shop and have them look at it. Problem, bad waterpump. So now it's been replaced but it's still leaking. They are saying the engine is rusted/pitted where the gasket/waterpump mounts and they need to sand it down so it's flat and place another gasket to make up for the sanded down area. Does this sound right? I am a bit scared and thinking about taking it somewhere else. Please someone chime in on this issue as it's at the shop now and need to figure out if I should keep it there or go elsewhere? Thanks!
1) That would have to be awfully bad to leak w/a new gasket.
2) If it were that bad, why did they assemble it just to watch it leak?
3) A thick skim of black RTV & a new gasket can seal almost anything, even pitting/roughness, w/o excess "squeeze out"
see 1&2 above.......................................
4) If it is that bad & needs leveled, then what SSD posted is it to correct it properly on the car.