RE: RCAero JC Engines & YDA Engines
Some of the earlier 28's were delivered with the corresponding hole in the carb blocked to stop the crankcase pulse going via that route. Check to see if yours is one of those. If it is, the hole in the gasket is not an issue.
If you can't find a gasket without the hole, Some of the gaskets can be turned so as to block the gallery. Otherwise a dab of JB Weld or a lead plug will work to block the gallery.