Hi Sammy,
There is a company in Oz (Adams, I think but I'll try and check) who make adapter plates - Chevy to Toyota. I guess they would know the options available. If I can't find the name then worth a call to F'n'B.
As far as I'm aware the differences between a 47's box and a 60 box are just the number of gears so you may be able to use the shaft handbrake set up. 60s have the h/b on the axle but the axles are only 70mm wider so may be worth considering an axle swop.
Keep the photos coming
Regards,