Going to a firm specialised in welding will yield mainly overworked firms that don't have time for small work. Or they'll just tell you no, or will add such a pricetag that it will make your head spin.

Better bet to find a welder that will exchange skill for other stuff than money. And those you can find in repair/maintenance departments of larger firms. (I'm judging on myself in this case)

I can't help directly with welding stuff, I'm a tad out of range. Like the next country over the sea.