[A/S] Airstream Sheet Metal Type and Source

["Jim White" <appdsgn@xxxxxxx>]

Hello list members,

My 1984 Airstream motorhome has about 4-5 inch tear or crack in the aluminum
sheet metal emanating from forward (about 2 o'clock) of the top of the door
frame. I have no idea how or when it happened.  It could be a botched past
repair or much or a tear in or stress crack in the metal. A crack seems a
bit extreme, as I do not think the metal would get that brittle.  The coach
spent most of its 17 years in AZ.  Regardless, I plan to repair it by
drilling a whole at the very end of the crack and riveting a new piece of
sheet aluminum over it.  For appearances, I'm thinking of extending the
patch symmetrically over the top of the entire door frame.

My questions are:

How is sheet aluminum designated?
What type of aluminum did AS use in 1984?
How thick?

What are the sources (retail / small quantity) of the material?
What are typical order quantities?
Any idea of what costs will be?

How is it cut .. will tin snips work?

Any assistance or information you can provide is appreciated.

Thanks Jim

1969 Overlander pulled by a 1999 Yukon
1984 Airstream 345
WBCCI 4914 (recently joined at large)