Wow that's alot of miles. I would say if it is original, the likelihood of necessity for a replacement of your clutch is high. However, There is probably one thing you can try first to determine what's up. I would try and bleed the clutch before I would condemn it.
I am not certain, but it would guess that your clutch is hydraulically actuated. If it is, you would need to raise the front of the vehicle off the ground as high as you can safely get it, have an assistant help you by pumping the clutch pedal, and with the assistant holding it down, you to turn the bleeder screw open until the fluid squirts out (brake fluid). Don't let the assistant let up on the pedal until you tighten the bleeder screw and you are sure it is tight and you say so. Good communication is the only way that this will work. If you see lots of bursts of air, like splatters and sputters, then there is air in the line that is preventing the clutch from performing properly. If it continues to spurt and sputter after repeating this process close to a dozen times (don't forget to fill up the fluid reservoir as you go), the problem is likely that air is leaking into your clutch system through a bad line, master cylinder, or slave cylinder. These are usually less complicated and expensive to replace than a clutch assembly, so this is why I would start here first. If there seems to be a steady stream of fluid throughout, especially since beginning this process, then I would say you need a clutch job.
Clutch jobs usually require a throw out bearing replacement, inspection and possible flywheel resurfacing or replacement, as well as a thorough inspection of all other clutch actuating components. It is alot of labor to get it apart, so you don't want to have to do it more than once. Sometimes you can get clutch kits that have the pressure plate, clutch disc, and throw out bearings included. These are usually the best way to go, but don't forget the other stuff. Another thing to inspect while the trans and engine are separated is the rear main seal on the engine block. If it is leaking, be sure and replace it as well. That can affect the operation and longevity of your clutch. If you pull the axles, make sure you know if the differential will keep the spider gears in place, or if they will fall. If they fall, you might want another shorter shaft on hand to put in place to keep the gears from falling down. They are a real pain to get back in.
This is general clutch job knowledge and may or may not apply to the specifics of your ride. It is a big job, and if any of this makes you nervous, have someone with some knowledge/experience lend a hand. It can be done in 8 hours easy if you have the parts and tools on hand. Otherwise, it could be a week or so of downtime waiting for stuff you find wrong along the way.
