Help with seriously leaky rockwell

[JJorgensen52]

I've been driving my truck on the highway a fair bit as of late, and aside from the fact that it vibrates a bit in the t-case (which I would expect from a gear driven case like the rockwell), when driven at speed (60 - 65mph) for any kind of time the case leaks gear oil. A considerable volume of gear oil.

That said,

1. What in particular should I be looking for in terms of leaks? It appears to be leaking both from the tranny - t-case adapter and the rear yoke retainer.

2. Are seals / gaskets still available to an extent that I can actually get this thing to stop leaking? I've been super happy with it and would rather not change it out.