Here are the manuals for the mil-surplus AB-621 mast system.
The manuals are in PDF format. The manuals are
broken down into 11 individual files, the largest is
about 3 Mb or there is a zip file with all 11 files in it at about 9 Mb.
Click
here for the big zip file (~9 MB)
Individual files:
AB621 part
1
AB621 part
2
AB621 part
3
AB621 part
4
AB621 part
5
AB621 part
6
AB621 part
7
AB621 part
8
AB621 part
9
AB621 part
10
AB621 part
11
The smaller users (field) manual. Lots of drawings that might be of use.