Have been to the British Isles many times and love the regular grub.
For 40, could make a cottage, or shepherd's, pie. Can easily be done in caserole mode and serve with some HP sauce. Add a salad and you are done.
Or every pub serves jacket potatoes. They are only baked spuds with a choice of toppings from chili or shrimp or cheese. Could do a tater bar. Just Google for authentic' ideas.
Love bangeres and mash but the British banger tastes different than most of our sausages and you would have to order them on the web unless you have a local source. I don't know of one in N VA.
Scotch eggs are common all over Britain although I frankly do not like them.
Or can serve a ploughman's lunch buffet style. Very simple .
I suppose steak and kidney pie is out but they are good.
And I won't even mention haggis (OK I mentioned it). It is truly Scottish though, but we love the stuff. But you cannot get anything approaching the McCoy in this country (something about sheep lungs, the feds don't want us to eat them).
As an aside I beieve the deep fried Mars bar (their Mars bar is a bit different than ours) originated in Pasquale's in Edinburgh. Always meant to have one but for some reason we never have.
Am sure you will have a great success.