That is a nice watch you have got there!
As far as I can tell, the 601x Bell-Matic series came on two different bracelets. One is depicted in John's photo above,
the other one is shown fitted onto the blue and silver SGP 601xs in the ad attached (picture taken from John's former bellmatics.com page).
This (Stelux) wide-link bracelet is IMO of particularily high quality and is most probably the sturdiest of all Bell-Matic bracelets...
Best,
Hermann