CS1 cambox cover

Hello all. I have managed to buy a 1933 CS1 and I am in the throws of getting the beast running. Found a few gremlins but nothing really serious. I did, however, find that some kind soul had hacksawed off the decompressor boss on the LH cambox cover. its basically a round hole on the front. My question is - would it be good to weld this ( don't like this as its might distort the bearing alignment! ) or would anyone know where I could get another cam box cover? All the best. RObert