As an aside, out walking the dog today and noticed a chap has three Triumph Spitfire chassis laying in his drive way, chained together. And a scruffy dirty looking glassless car with a fast back on, and a roll cage inside.
So if this subframe is off a Spitty, I know a man who probably can.
See below
In my opinion if it isn't an excellent, ideally invisible, repair I wouldn't bother.
As an aside a mate has a old focus estate that failed it's MOT because of corrosion to the front cross-member.
The tester went out of his way to batter a hole in it and he told him not to get it welded.
My mate didn't tell me until after he had a second hand one fitted.
I was gutted because I would have welded it and let the tester fail it, then appealed his decision for a bit of fun.
He only keeps it as he bought it new and doesn't really need it so we could take the time to mess.
6 Highly stressed components
The severity of corrosion in highly stressed components, such as steering and suspension arms, rods and levers, can be assessed by lightly tapping or scraping with the corrosion assessment tool.
In places that can't be reached by the corrosion assessment tool, an alternative blunt instrument may be used.
A highly stressed component should be rejected if corrosion has resulted in serious reduction in the overall thickness of the material or has caused a hole or split.
Welded repairs to highly stressed components aren't normally acceptable, other than where the component is made up of sections that are welded together. To pass, the repair should appear to be as strong as the original design.
Hi, The MOT tester manual says (section 2.2) a reason for failure would be for 'inappropriate modification or repair or use of excessive heat by welding to steering or suspension components'. That's very subjective and open to interpretation.
If the rest of the vehicle is sound [unlikely] then persevere with it if that's what you really want, otherwise scrap it and get a better project car, plenty around cheap.