I'm pretty much with everyone else here that as far as the studs are concerned rust isn't an issue and a wire brush on a drill will clear things up. With the proviso that if after wire brushing any threads are obscure then the rust was too deep.
Now how much force did they need to remove the nuts? 3/8ths studs are only designed for a tightening torque of 42lb/Ft. If big forces have been used then the studs may have been damaged. Though I'm not as bothered by the twisting force as by the stretch to the stud when it is tightened to over 42ib/Ft with a windy gun. Sorry for not being committal here. I know the issues but I'm not a good enough engineer to say what is too much.
With respect to the brakes: Unless they had received the mother of all hammerings they will just require adjustment. This is good as pre 1989 brakes can be very costly. You use 160mm X 35mm brakes. See the price difference here: [You must be registered and logged in to see this link.]
From a kit for a full axle at £64.96 (K16035) For post 1989 to £58.98 for shoes for one side with no springs (WB S22) For pre 1989.
Sorry for this last bit I know you say you are not technical, this is more a book mark for me.
We have seen prices for pre and post 1989 Knott brake components but looking at Knott's own website it appears that there were pre 1988 brakes. 1988 to 1990 brakes and post 1990 brakes.[You must be registered and logged in to see this link.]
Pre 1988 [You must be registered and logged in to see this link.]
MK 2 1988 to 1990 [You must be registered and logged in to see this link.]
MK 3 1990 onwards http://www.knottuk.com/fileadmin/Knott-UK/usr/pics/Products/Brake_Shoe___Spring_Kits/Brake_Shoe___Kit_-_160x35MK3.pdf
Wonder why we only ever see two types quoted if they built 3?
Last edited by Tow Itch on Sun 29 Sep 2013, 10:23 pm; edited 1 time in total