while my mk1 was stored i replaced the standard xflow rocker cover with plastic cap for a shiny polished one. since bringing her out the engine has squirted oil through the dipstick hole. the new cover has a screw down cap. did my engine breathe through the old cap??? turns out as well that the old cover has been binned (not by me!! ) so i can't test that theory.
PLEASE HELP AS READY TO GO BUT WORRIED ABOUT BLOWING SOMETHING AND THE MESS!!!!

additional...... have removed and checked breather pipe to carb and non return valve, valve seems to move up and down freely by hand, pipe is not blocked and neither is the carb spigot.is it possible the breather box is blocked??