Maybe some other parts store carries "Dorman OE Solution" stuff. Dorman has a
cover & gasket kit. Maybe there is a store with that thing in stock closer than the Honda dealer. The whole thing is about $57
Or you can get the gasket maker and apply it carefully to the cover so it's smooth and slightly bulgy. Let is set up for a few hours. Maybe put just a smear of the stuff on the place where it mounts on the engine when you put it on. You should be able to get it together without gouging out the new "gasket."
You could use plain old weather strip, and replace it when you have the correct part and time. It ought to last a few weeks at least.
-mort