I just ordered a repaired stock driver's side header from Mike McCoy for $100. It should be here in the next week or so..
I'll let you know what it looks like when I get it in.
Any of the major Turbo Buick vendors should be able to point you in the right direction. I know Conley's does header repairs....I also talked to Ron Joseph at Ron's Custom Auto and he does repairs also.
Good Luck,
John