12 bolt rear end - brake question

[83burban]

I just picked up a 12 bolt rear end from an early Chevy truck, it is six lug and has the trailing arms. This will be going into my 62 to replace the 8 lug monster that is back there now. I want to do a disc brake conversion on it while its out.

On my 8 lug the drum brake backing plate is bolted on via the flange at the end of the axle tube. On this one, there are no bolts - was this something that was pressed on or welded on? I don't see any welds there, and I thought the backing plates were bolted on at the flange on all axles.

What do you recommend for caliper mounts, the weld on types. I know I can google it and find a bunch but who makes the nicest parts that will fit. Thanks