It is a good design, Mercedes & Volvo have been using in the rotor hat type drum type p-brakes as far back as I can remember them having rear discs. Corvettes, Explorers, Ford F-Series, and the full size GM trucks also use this p-brake design.
The only domestically used hydro-mechanical caliper that I know of that works is a Varga, but I do not know what the application is. I've no experience or info with the Asian hydro-mechanicals. FROF used to (still does?) offer a Mini rear disc conversion using Supra hydro-mechanicals. I'm interested if anyone has experience in using those.
I'm hearing from a well respected vendor that the 80 series set of parts most likely are not a bolt-on and worse, probably would require grafting the 80 stubs to a 60 housing. No info on simply adapting the calipers & brackets to a 60.
I think you mean FROR.
I did a rear disc brake conversion on an 89 Toyota pickup 2 summers ago. I was going to use the supra rear disc calipers that have built in levers for the e-brake. I was able to find a lot of info , but all the part store around my area were not able to get them ordered for me.
They would be from 79-81 supras with rear discs.
you would have to use rotors from 79-85 4x4 toy trucks for SF land cruise rear disc. They are floating calipers.
We recently bought an HJ60 which I would like to change to rear disc.
maybe this summer I will be able to locate those Supra calipers.
There are other calipers that work in the same maner.
89 Corolla with rear discs , I was able to locate them ,but the levers are offset , so still the supra calipers are better, because they have the levers in the right location.
For SF rear or FF this would be where I would look to do discs.
Making a caliper bracket should be easy to do.
All this info I got from looking at pics ,searching on the web and taking to the parts guys. So even though I can't confirm it, I think it is worth looking into.
I have posted about this few times on mud, but never got any feed back with more insight, just more questions.
You can talk to Brian at FROR , he might offer more info on the Supra calipers.
I had a chat with him a while back he was very helpfull with info.
Vic