Morning Mistakes. Gotta love the money suckers

[low&slow]

So first thing was first. Put my new carb on, then the mistake happened. A washer fell into the intake manifold and I can't see it. So I got to pull the intake. Well, I don't have the money to go buy a new one (500 caddy parts are expensive around here) so I'm wondering if there would be a way I could just make one until I can get the money????
This truck is only going to be started maybe 4 times if that till I get the proper gasket. I just need something for a test fire as for it hasn't been started in a little over 4 months. Any help appreciated