One thing that I have learned about these tractors is this. You cannot make very many "absolute" statements about the year of the tractors. I have teeth marks all over my ass as a result of making such statements. As an example, I used to think that all 1976 tractors had a bump-out on the left side of the hood for the exhaust. After all, that's what the brochure indicates. I used to think that all 107/117 LT's came with a fake hood scoop. After all, I have a brochure that shows the hood with a scoop. I could give you several other examples but there's no point. Colt, Case and Ingersoll did whatever the hell they wanted to without regard to the calendar year of the tractor. I'm convinced that a lot of the decisions were based on using up existing inventories of parts.
Take the travel/lift valve with holding feature. You would think that Bill Schlapman would have sent a note to the production line that said " Guys.... we will stop the assembly of 1984 tractors on August 30th and begin the 1985 models the next work day. You will begin putting the new holding valve into all of the tractors from that date forward. " HAH..... think again. If you look at my FAQ on the holding valve, it shows all kinds of tractors being built prior to a certain PIN in a given year. Some models got the new valve right away while others had to wait until the following year.
In many of my posts to members asking questions, I try to make them understand how important their PIN is. There are numerous instances where two parts manuals apply to the same model year. Not every 1976 Case 446 came with the oil tank under the battery and not every 1977 Case came with the steel oil tank under the battery. Where this is especially important is when you decide to buy used parts off the internet and foolishly rely on the year of your tractor and the year of the donor tractor as being an absolute assurance that the part is correct. Big mistake. Always get the PIN of the donor tractor and look up the part number so you can compare it to the same part in your parts manual.
The first sleeve hitch for the 200/400 models was the F model. If a dealer had a brand new tractor sitting in his showroom and a customer wanted a sleeve hitch, then he is going to ask his parts guy if he has a sleeve hitch in stock. If that happens to be an F model, then that's what will get put on the tractor even though Case may be issuing the J models that year. If it works, it works... and that's all that matters to a dealer whose main objective is to turn over inventory to keep it fresh and up to date. Having thousands of dollars worth of NOS parts and accessories gathering dust in the parts department is not a smart way to run your business.
You have to make use of the Tech Library to sort this out.