Looking for Recon Auto Box for 1995 Monster Surf

[Hilux Monster]

Hello everyone,

Not sure if this was a good idea yet or not haha! Its quite a beast and although it does work, it wasnt apparent during the test drive that 3rd gear had issues, or that there was a small hole in the diff. 

I'm looking for recommendations for suppliers for recon automatic boxes, or any tips as to what might be wrong please. At higher speeds there is a scraping / grinding sound when releasing the accelerator... and sometimes when accelerating at higher speeds (particularly if on a slope) the revs suddenly go very high (nearly in the red), almost as if it has dropped into second and wont go back into 3rd. Slowing right down can kind of reset everything. Its a lot more comfortable on the motorway than the A-roads. Around town is fine so 1st & 2nd *seem* ok but there is still some scraping / grinding when lifting off the accelerator in 40 mph zones. I'm not too familiar with auto boxes, so dont know what is happening.

I'm also struggling to work out the correct fluids for the gearbox, transfer box and diffs. The garage are proposing to weld the hole on the rear diff and switch the auto box for me if I find another, but told me to find the fluids. Of course Euro car parts have a two hour wait on the phone at the moment and they and another site differ on the oils they recommend. Really dont want to get it wrong, so be great if there is a resource for this, or if anyone knows exactly what I should get?

Thanks very much in advance for any advice!

Alex