K20 Questions on a Frame

[Seanext]

Ok so here we go. I needed a frame for my 71 K10. The current frame has been repaired several times over the years for rust issues so the search was on for a frame. Another board member located one for me in KY about 5 hours away. Went and got it yesterday, in the southeast so we have been flooding here and more rain over the next two days. Frame is still on the trailer been trying to get out and take pics but just want stop raining. As soon as it breaks I will post pic to help with the questions.

Here is what I know so far.
The frame is a long bed with 8 lug axles.
Had a step side bed on it.
It is a true 4X4 frame not converted.
Vin tag was gone from the cab so no help there.
The serial number on the frame starts with 0 so I am assuming it is a 70. There is the correct bumps in the frame for the power steering mount.
It has a 292 cross member.
Has power steering gear box.
It has the bracket mounted to the frame for automatic and not one for the clutch pivot on the frame rail.
Has a 8 lug closed axle Dana 44 I assume.
Has 8 lug Eaton HO52 I assume.

Here are the questions and know this thing is 46 years old and parts could have been changed over the years just wondering what "could be" original.

1. It is my understanding that a 70 should be open knuckle with drum brakes? Again will get BOM numbers and pics when I can. Were there 70's built with the closed knuckles?

2. Will the numbers on the Eaton tell me if it is a HO52 or HO72? if not how do I tell which one it is? My understanding is HO52 were 3/4 and HO72 were 1 ton but there is a lot of conflicting information on this one. Also will the numbers tell if it is no spin.

3. How rare would a 3/4 ton 4x4 292 with auto and power steering have been?

4. What other information can gather from the frame to tell me exactly what year it is and any other information

Ok the monsoon stopped for a few minutes and got this pics