A couple 71/72 cab and vin questions.

[CG]

Are the door jambs the same on 71 and 72? I have that black plastic vent thing on my 71 door jamb and it has a couple of chunks missing off of it, need to know if its a 71 only thing.

This was once a motor home and there is no rear view mirror. The pad is there and the holes to mount a mirror are there. It may or may not have had one originally (doesn't look like it), it would have been useless on the motor home anyway. I was curious is the 72 different right there (mounting pad?) since the mirror is mounted on the windshield?

Lastly can you clean and polish a vin without messing up the blue lettering? There is a little paint on this and I would like to give it a nice sprucing up. And come to think about it the vin for my 71 SWB K10 also has a bunch of paint on it that would be nice to get off and give the vin a nice polishing without messing up the blue lettering on it.