Actually, the D30's passenger side perch IS cast into the housing... it just not INTO the housing like the D44... Take a look some day... or I'll try and snap a picture here...
As for parts, what did you pop?? The locking hubs are the same as the Scout II D44's, and the external Jeeps hubs (CJ's), pretty damn common and anvailable new from many sources.
If it is the wheel hub you busted... disc or drum?? 90% of the Scout II D30's were drum (years '71-74ish). There were D30 disc units availiable around '74, but you could also have ended up with a drum D44, or a disc D44 (what ever they had at the time). The D30 disc set up is the same as the D44 disc set up (Scout II). The drum hub is "simular", but the back face is not machined like it is for the disc, and the wheel stud holes are bigger.
The D30 drum spindle is the same as the D44 unit, however it is held to the knuckle with 6 bolts, not 8.
What part to you need??