I did something similar when I bought my first scoob, had a crappy plastic knob on it so I ordered a leather one from ebay. Anyway, when it arrived it didn't fit properly, it had a massive gap between the knob and the gaitor
So at work one day I noticed an old rusty spanner socket on the shelf and thought ahh, that'll do for my gear knob.
So I shined it up with silvo and stuck it on, filled up the gap nicely.
Replaced it with a Momo one not long after,
you can't beat DIY car mods though