Items needing fixing - suggestions? steering box, heater, radiator, shocks etc

[centuryhouse]

I bought my first GMC pickup (72 Sierra Grande long bed w 350 4-barrel, factory AC, etc.) last week and have done a few repairs already, but have lots more to go in order to even get it moderately drive-able. Suggestions appreciated.

1) radiator has a tiny leak where the upper hose attaches. Someone tried to putty over it, but it still leaks a tiny bit there. Radiator shop wants $165 to braze it, or $50-ish if I take it out and bring it in.

When is it worth replacing vs fixing? Is it likely to have more problems if I fix it, given it's age?

Also - mine has two metal hoses going to it (automatic transmission I think), the upper and lower hoses, an overflow hose, and one other hose on the passenger side that is capped off. What is it for?

2) I replaced the leaking power steering hoses, but there is still a leak, albeit smaller. It *appears* to be the steering gear box (?). Neither hose connection is leaking, yet there is a puddle underneath and the gear box and adapter just above it (between it and the steering column/shaft) are both wet.

I don't know how these work. What could be leaking in that gear box or the round plate (rag joint, I think it's called)? Best to just replace both? Difficult to do? Suggestions on parts or can I just get a direct replacement at O'Reilly or wherever?

3) the shocks look ancient. Any suggestions on replacing all 4, or will any O'Reilly's available part do well? Any fit problems typically, or hard to do?

On my Jeep XJ I just installed Monroe Sensamatics and they seem to ride well. Good choice for this?

4) The plastic door panels were 'parchment' and look grungy. They seem to almost crumble if you scrape them. Better to replace with new, or refinish? Tips or suggestions?