I've been Lincoln Locked front and rear for a few years now, no problems (D30 and D35).
Have somebody weld it with a 220 MIG for good penetration, I tried Arc welding and it didn't hold as well. Make sure they fill all 8 corners where the spiders mesh with a LOT of metal.
Only prep work I did was a good cleaning with carb cleaner, then air.
You may not find a shop that will do it due to liability. Small town shops may be more likely.