If you still have not made any moves on your Fintail exhaust then I would contact Mike at TimeValve.
His systems are the best... All stainless.
Stainless is louder exhaust note then steel and will perform as good as any other system.
I have used his products for many years.
He made a system for my 1963 220seb and the fit is excellent.
Here is the deal though... More than likely due to variations in the these cars he will need to furnish the foremost part of the system the downpipes unasssembled. You will have to fit the system and then tack weld the front pipes, then disassemble the system and then fully seam weld the front pipes. That's what had to be done with mine.
He is an excellent human being (great to deal with) and has the best product. Builds mainly Ferrari and Benz systems as well as many others.
If he does not have the pattern and you do then send him your old exhaust and he will make it.
see:
http://timevalve.com/http://timevalve.com/cat/us/uscat.html