With standard velocity .38 Special and the grips that are on it that 49 it shouldn’t be too bad to fire since it’s a steel frame. If you aren’t used to recoil it may seem a bit much. S&W is claiming that guns shipped for non-warranty work may take up to 6 months before they are repaired and returned per a conversation I had with them a while back. I doubt their lead times have diminished. For surface rust I have used WD-40 and 0000 steel wool. I have also used copper Chore Boy pads and WD-40 to get rid of rust. Be sure and use a lot of WD-40, Kroil or whatever you use. Whatever you do you won’t be left with a blued finish where the rust was but keeping the gun oiled or using a silicone rag on it will help keep rust from returning. I think you got a pretty good deal on those 2. You’re going to love the model 15.