Idle musings at the kitchen table...
An interesting thing is a horse shoe.
For luck, the shoe must have been thrown i.e. New horse shoes aren't much chop when it comes to luck. So. The horse shoe must've had a physical connection to a horse for it to be considered lucky.
The Forge, or the Farrier/Smithy has no connotation with luck, but a horse shoe must be hung, open end down, over the forge to imbue it with luck/good fortune...which is the opposite in any other situation.
In conclusion, can we say that it isn't the shoe, the forge, or the Smithy that imposes or transfers good fortune, but the fact that a horse was once shod with the shoe, and then that the shoe was thrown.
It's a funny old world, innit.