hi bonnar bloke I will try to explain the the repair for you more simply sorry no pictures
after scott has made new rails its easy to simply fold up two smaller rails about 7inchis long
place these smaller rails inside the new replacement rails.
these smaller rails are to be stich welded in under were the motor sits.
these smaller rails work as gussets under where the motor sits and stops the common fault of cracks around the bolt holes as with the gussets you double the thickness of the rail where its prone to crack
metal thickness used for the new rails and smaller gusset rails should be 2.5mm to 3mm thick
welding on the gussets smaller rails should be stich welded that means weld 20mm miss 20mm weld 20mm and so forth till gusset rail is welded in.
best method is to weld a few stiches on one rail gusset then weld some stiches to the other rail gusset
that way you lesson the amount of heat when welding in the rail gussets as welds and metal shrink causing buckles bends in the rails and we don't want that
this is a repair I have done quite a few times over the years and we always checked the rails during servicing and never had a machine come back with any more cracks after the rails were double strengthed this way
I hope I have made the repair more clearer for you to understand I know a picture would better explain it for you but it really is a simple repair once your done it a few times