Repairing rusty rocker panels

[Vangelis Kokkevis <vangelis@domain.elided>]

The passenger's side rocker panel of my 83 spider has developed a case
of terminal rust from the front wheel to the rear wheel well... Pieces
are peeling off from the bottom so a repair is (over)due. I checked out
a few sources and it seems that IAP has the most complete (most
expensive too) solution.  They sell a complete rocker panel as well as
the front and rear fender parts I need for the repair.  Unfortunately,
one or two of these pieces are out of stock.   Centerline on the other
hand sells the skin of the rocker panel that extends from the front
wheel well to the rear wheel well for about 1/3 of the price of the IAP
parts.  Does anybody have experiences they would like to share with
respect to rocker panel repairs?  I will have the repair done by a body
shop, I just need to get the parts myself since the shop is not that
familiar with Alfas.  Are there any alternatives to IAP and Centerline? 
Are IAP's repair panels worth their price?  The extent of the rust is
pretty significant (east coast car) as far as I can tell, but I guess I
won't know exactly how bad it is until the shop starts taking things
apart. 

Thanks
Vangelis
Santa Barbara, CA
83 Spider
85 GTV6

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