[Tigers] Welding broken original manifold?

[Would U. Believe]

I have a question for anyone with experience in welding or having cast iron
parts welded.  Some guy sold me a set of original Tiger exhaust manifolds
and one of them (the right one, of course) had a crack in the flange where
the stud to the down pipe goes.  To make things worse, the guy also ground
down the area for unknown reasons, removing about 2 to 3 mm of material,
which further weakened the area.  Now you could guess that the flange broke
off when I tried to tighten the down pipe to the manifold -- and you'd be
right. Ugh. Since I'm not at all interested in communicating further with
this particular seller because he seems unreasonable to me, I've decided to
focus my energies in investigating whether such a carbon-soaked part could
ever be welded successfully (considering about 40 years of hard use). Does
anyone have a positive experience in repairing one of these old manifolds?
Does anyone know someone who'd do it (in the States)?  I'd rather try to
have that done than toss the thing into the trash bin and buy another one.
Yeah, this was and is all a big waste of money, but it's worth a shot if
only to try to prevent an original Tiger part from being trashed.  Please
let me know what you think.  Thanks.  M