If your mum was a hairdresser but just didn't specialise in styled men's fashion hair, but got it right regardless, what's the issue? Would you go and get it cut at a barbers to get it even righter or would that be a waste of money?
It's a toothed belt regardless, it's either a tooth (per pulley) out, or it's not, and if it's been done, and it's running fine, then it's not