When I look at damage like that I have to wonder how long somebody drove that vehicle whilst the planetary set was grinding itself into dust.
Yes, the trans can be repaired. Throw the planet, reaction shaft (ring gear) & sun-gear, & plastic thrust washer (between sunshell & sprag race) all in the trash. Tear the entire trans down and wash it until there is no metal left inside the case, or any of the parts. You will need a complete clutch set as there is metal imbedded in all of them by now. You will need a band. You will need a complete bushing kit. You will need to disassemble the governor and remove all metal from the barrel and polish the gov. valve by chucking it in a drill and holding it against 1000 grit paper. Replace all the screens in the case-2 of them under the valve body, and 1 in the pump. With that much metal in the trans, your pump will probably be scored. Your trans cooler inside your radiator is probably littered with metal. Get an external cooler and bypass the trans cooler if you can't get it flushed of all metal. You will need a new converter. You will need a bearing kit as I would not risk running any of the bearings now that they have metal inside them.
More importantly-what caused this? Pull the seal that rides inside the 3rd & 4th clutch drum. It will be under the bearing that the input sprag assembly rides on. Is it a hard plastic seal? My guess is that it is/was. It is probably damaged and caused a lack of lubrication to the rear planet set. When you rebuild it, if you rebuild it, DO NOT use a hard plastic seal there. Ask for, or order, a Viton seal as is used in the 4L60E's. Good luck with your transmission.