Does your replica use the Pinto Evap system? Is there a Charcoal canister and line to the fuel tank? Usually this problem is a result if the tank being over filled and eventually overwhelming the vent line with liquid fuel which in turn causes the charcoal canister to saturate and prevent proper venting. Also check the entire vent line for kinks and hoses collapsed. The canister may have gone bad and needs replacement or renewal (Activated charcoal replaced, it doesn't last forever). The vapors during refueling have to go somewhere, and if the pump nozzle isn't pulling them out fast enough, you get the kickback overflow with the ethanol added fuels. It's also possible the tank vapor separator is plugged.
I still haven't solved this problem with my 84 Vw GTI, and I've been through the whole system.
Pintosopher , always venting but seeking solutions