A couple of comments on the 1943 quotation.
1. I haven't seen it before, and am amazed at the audacity to claim it is the Lord's direction. I have to laugh at the final statement:
This expression of the Lord’s will should be the end of all controversy. It is for your good that these requirements are made; for thereby you are enabled to prove your integrity and magnify the Lord’s name LOL
2. Considering the historical context. Rutherford had died in '42, and very soon after that it was a priority of the WT organization to get the brothers a minister qualification for the draft. WW2 draft was issue #1. This is quite clear from reading the book Jehovah's Witnesses in the Divine Purpose. They didn't have a lot of success in getting the minister classification; loads of the brothers were in jail. The made several organizational changes in the war years and into the '50s to give the brothers something to present to their draft boards.
A couple of the objections they were facing:
You don't have any training - The WT organization invented the Ministry School
You don't have any WT books providing training - The WT published Qualified to be Ministers
You are only 19, how can you be a minister - All JWs are ministers
You have no proof you are a preacher - Here are my written records of the hours spent in ministry
You are not fulltime - WT invents the 'pioneer', with specified fulltime hours
It was all about the draft back then. The 1954 Walsh case is worth a read as well, where it is clear that they were trying to maneuver their position to support their legal stance towards the draft issue.