the forward clutch is toasted in your box, it will also display symptom of no reverse or extremely slipping reverse. Rebuilding it will cost you near to 25K to 35K but you will essentially have a brand new gearbox in your car.
your problem right now is
1 - mechanic to rebuild it
2 - parts to rebuild it (dont use scrapyard/junked/used friction plates and seals in your overhaul - its plain stupidity)
your workable option right now is to take a chance with junked gearboxes and see which one works, You might need to swap 2 or 3 times to get a good one. - In all cases dont opt for a 660 unit as the gearing is different and you will hate your life.
Find a transmission cooler from the yard too, old pajeros, cressidas, crowns, land cruisers etc had them. Its a really good investment to protect the gearbox because yours is tiny, has a tiny oil capacity and gets cooled by a tiny pipe in the tiny radiator - and we all know that 90% transmission failures are heat failures.
Install the extra cooler after the original radiator one to get maximum effect. Dont eliminate the radiator cooler - as your transmission does require to warm up too.