[Boatanchors] Recommended replacement for rubber tuning bands?

[David Colburn]

I 've acquired a Heathkit SB-101 with the rubber tuning

bands laying, somewhat dried and broken, on the board.

They roughly measure about 7" - but that may be off some

due to age and stretching.

I seem to recall that large rubber o-rings used to be their

recommended replacement - is that still the case?

What is the tried-and-true best replacement and at what

length, please?

Thanks,

David, KD4E