Welcome to the 'bolt!

I'd check a few things here. Rough idle could be as simple as an idle screw adjustment on the "B". That's the screw that is at the base of the carb facing the head. Turn it clockwise until the engine runs rough (rougher) then back it out until it smooths out.

Also, check the obvious things, firing order (distributor wiring to the plugs) and timing. Is the air cleaner element clean?

If none of these things reveal a problem I'd do a compression test next.

Hopefully there'll be some more suggestions coming soon.