Monobaths have a long long history (decades before 1967)
They are no more than a mixture of developer and fixer, so if you want to try a monobath, there's no need to buy one from New55 or whoever.
Just google* for "monobath formula" and you'll get plenty of hits, and then you can buy the chemicals and make one yourself.
Have a look on APUG, there are dozens of threads about monobaths and the various complications and shortcomings thereof. They really have to be "tuned" for each film.
If you really want the lowdown on monobaths, get a hold of Grant Haist's "Monobath Manual".