83 4MT stuck in 3rd / options needed

[nontrivial]

My 83 Brat has an 81 wagon 4MT dual range transmission of dubious quality, namely it is super sloppy even after replacing the pin in the linkage with a bolt. I know the wagon it came out of, and it had a hard life. It is very difficult to get into reverse, to the point that I removed the dual range 4WD linkage to increase the chance of getting into reverse. It is very easy to get it into 4th instead of reverse and normally it isn't a problem, except this time when that happened it went into 3rd and won't come out. The clutch works but I can't engage 4WD to test if that has any effect. I've tried manually wiring the clutched engaged (flying solo here) and trying to lever the thing out of gear underneath but it's stuck pretty good. This is my main transportation now, so the first thing is any advice on what to try would be appreciated.

The second thing is I've always planned on replacing the transmission at some point, and I have a replacement 4MT dual range of unknown quality that I'm going to attempt to swap this weekend. I'm hoping it's a good transmission with minimal slop which will allow me to engage the 4WD again. But just in case the replacement is a lemon, I would appreciate somebody more knowledgeable than me looking over some ebay transmission options to verify they would work for a plan B. I can't really find another direct replacement, so the options are:

a) https://www.ebay.com/itm/334256602954 - mythical 5MT 5SP dual range?

b) https://www.ebay.com/itm/143901400021 - this is for a later model, probably not kosher

c) https://www.ebay.com/itm/174524369221 - also for a later model, probably not kosher

d) https://www.ebay.com/itm/334256586223 - not 4WD, can I use in a pinch?

e) https://www.ebay.com/itm/334269076108 - maybe the best option?

f) another source you might know of

So to recap, I please need advice on:

• Any suggestions for my current transmission other than replace it?
• In case I need another transmission, will any of the above ebay ones drop in?
• Any other place where I can get my hands on a transmission?

[el_freddo]

First link, don’t like the generic advert with their generic pics. Avoid in my book. Same for the 4th link. 

Second and third are EA82 single range 5 speed 4x4 gearboxes. 

Last is the EA82 dual range 5 speed 4x4 gearbox. 

The EA82 five speed will need some mods to fit to the EA81 platform. There are many threads on here about how to do it and it seems a good mod to improve drivability and the gear change feel is more car like than tractor... 

I’d go with the last link of those gearboxes as its dual range. Grab the rear diff or confirm that it’s the same as your current gearbox, should be 3.7 ratio in your brat. 

Read up on those swap threads to see if there’s anything else you need for the swap. 

Cheers 

Bennie

[nontrivial]

Luckily plan A worked and the replacement 4MT transmission turns out to be a pretty decent replacement. I eventually want to put a 5MT in it, but I'm not in a rush now.