Those sockets look to be correct. I've not had to replace any of the GI lamps, but have had to replace the insert lamps. The insert lamps are typically the long bracket ones. As far as the caps for holding down plastics, you can go with either. I prefer the push down style since they are easier to install/remove than the acorn style nuts.
For posts, I can't recall which post style bally used for this era game, but check out pbresource and find the correct post. Pinball Life may carry the same style. Note that the heights of the posts may be different so double check just to make sure.
http://www.pbresource.com/posts.html
Bay Shore, NY
