Larry,
Not a problem, I ordered the Skylight from Beaver in Bend, the inter and the outer part of the skylight is one piece. They had it in stock.
The procedure is straight forward, remove all old caulking, remove the 30 + stainless steel screws, skylight, double stick gasket, clean the surface. Use the 1 1/2 " wide double stick foam gasket replace the 30 odd SS screws, apply new sealer, then open a beer. Cost the Skylight was around $130.00, + shipping + boxing. The final number from Bend was about $190.00.
It was a good project, our skylight had small cracks around the flange and so many little fracture cracks you really couldn't see out. Now the Sun just shins on in.
Good luck,
Bill