Have you priced the brass plate, just might be worth enough to buy a new portable welder. the metal costs are raising.
And to you Mith, I weld where I need to. I like welding inside with the A/C if the part is small enough, otherwise in the shed. But if I have to, I take the Portable down in the field to what ever needs welding, but I don't care much for welding in the sun, unless I have to. Surface rust on the table don't hurt anything. Out of Habit, I grind the table before I start a new project, just to be sure it is flat and has no dings, etc. I spend a few extra seconds where the ground clamp connects.