Guide flags

I have a set of vintage cars that still run well with the original parts. However, the cars were designed to run on track with a wider slot than the current standard, and will run in some stretches but the guide flag jams in other parts. Since they are somewhat of a collectors item I'd prefer not to sand down the original guides but rather replace them with a modern guide flag. The problem is that there are so many guide flags out there and so few slot car stores in our area that I have a hard time figuring out what would work best for these cars.

My question to you, and especially the builders among you, is:

Would/Could you bring your (box of) guide flags to the next race at Randy's? I will bring the cars and we can match guide flags to these cars. Once I know what guide flags works best I can order them online.

Thanks!