Hi there - Beautiful looking frame! I've read that jamming a piece of wooden broom handle up the fork steerer tube was a precaution deemed essential by professional continental racing cyclists (Europe) in the '60's and '70's. The team mechanic would treat every new frame in this way. This was to hold the thing together if the steerer fractured, long enough to stop the forks coming out before the rider could stop. This came to light when Tom Simpson's bike was acquired by the Tom Simpson museum in Yorkshire, many years after his tragic death in the '67 Tour. Initially there was some natural doubt as to whether it was the genuine bike , but Tom's mechanic Harry Hall positively identified it from the piece of broom handle he had put in there years before! I can find no records of whether this ever actually worked, although in the 1950's there are quite a few references to crashes from broken forks, so it might have done the trick. This could be an indication that your frame has a racing history?