Auto Transmission Fix Options

I have slip and overheating problems with my auto trans on a 2005 RA Rodeo 4X4 diesel. I have changed the fluid (was brown now red) checked the pan and filter for debris ( some sludge around the magnet, no metal flakes, dark coating on parts). I took out the valve body dismantled, cleaned and checked all components, reassembled, refitted. Test drove, seemed a little better at first but engine still seems to rev a bit more than it should and takes a while to '"catch up" after gear change.
I can't have it of the road for any extended length of time. So does anyone know of a 2nd hand transmission (Jatco JR405E) 4wd or 2wd for sale I could change it out and rebuild mine.
Appreciate any other suggestions.