Scan it in sections, stitch the images back together in photoshop, and then redraw it.

Easier said than done, but that's usually the basic prep work.

For printing, a roll of banner paper would probably work--then glue it to cardboard using an aerosol glue (spray lightly or the glue will seep through the paper--I would practice first). Or, ask a print shop to print it. Depending on the type of print shop, they may be able to print it on a sheet of stiff plastic. I'm not sure if print shops really do cardboard. Most are geared toward signage, so they should have stiff plastic.

Seems like a worthy project to tackle. It appears you could just scan a single section, draw that pattern, and repeat it to form the entire banner, then change flag colors, etc. Can't wait to see the result!

If you don't mind spending a little cash. Go to a one day sign shop. They can print it on sign vinyl, which you can apply with slightly soapy water (1 drop per spray bottle) and a plastic squeegee directly to the cabinet. Only draw back long term, is the vinyl can tear. But paper tears worse.

Some sign shops can print directly to a sub striate like thin, .040 or .063 aluminum, which would be more durable on the game. But I would go with vinyl and keep the print file in case of a large tear or scrape down the road.