The canister only 'absorbs' fumes vented from the fuel tank I think. Does the TR4 even have a vented tank?
Usually there may be a vent line from the carb but this engine won't have that.
I'm not sure if there is a reason to have one, but if there is a tank vent line, any canister from any make of vehicle will work if it has...
A purge line.... just a vacuum line from the intake to signal the engine is running and to open the canister to empty it
A vacuum line from near the throttle so the fumes are thoroughly mixed with the incoming air
A tank vent connection.
This sould be enough.