Why the need to get down and dirty?
My suggestion wasn't trying to convince anyone it was just that......a suggestion
And there's absolutely no reason whatsoever this couldn't be made from rectangular box section, look at the stock piece, forget all the flanges and spot welds. As you know they just sheet steel strength once assembled, it is essentially rectangular, rad mounts can easily be fabricated and welded in the necessary place, any tapped holes for pipes etc can be made, tension rod mounts can tapped etc. it's really not a difficult job for a FABRICATOR as my post stated to begin with.
no raw nerves were touched I can assure you mate, but please don't expect me to say nothing about someone saying my idea shouldn't be carried out just because they are involved in Motorsport and their opinion is worth more than mine. the op didn't have to undertake my suggestion did he?
And fwiw lets consider how much of a Motorsport car is fabricated by individuals in a workshop, most of it? Why? Because if properly done it's stronger than stock....simples.