I know that some Ford tractors (prior to this era, as well) came without a PTO... or with the PTO optional. Adding the PTO after the fact... while it MAY be possible... I would think it would be so cost prohibitive as to render it impractical...
I'd wait and see what some of the others chime in with, though...
You will need the PTO support that comes out of the back of the trans and all related items, lever,cover,bearings, shaft, ect.
If all these items are available through the dealer it would cost you a good chunk of change.
Probably best to pick up these from someone parting out a tractor and replace the bearing and seals in needed.
You didn't say weather your tractor has a 4 or 5 speed tranny. PTO support shows to be different #s in the part book.
Best to look at a parts book to see what you will need. If you don't have one send me a PM and I can fax you the pages you needs. An IT repair manual will also have some info.
While not inpossible it will be some work because you will probably need to split the tractor to access the back of the trans.
Before splitting the tractor pull the side cover off to see if any thing is in there first. It could be possible, although highly unlikely with 300 hours, that the seal on the pto shaft was leaking and the PO took the shaft out and put a cover plate on. I doubt That this is the case but I have seen alot of strange things on these old tractor that will leave you scratching your head wondering what could the PO could have possibly been thinking.
You did not say if your 2000 was an LCG low center graverty model. If it pull a set of gang mowers aroung a golf course no pto would have been needed but it would have had a drawbar on it.
Gotta agree with what the others have said, the best way to add the PTO to it will be to find a tractor being parted out. Do as Kirk said, look at the parts book and compare to your tractor and try to determine what parts may or may not already be there. As he said you might get lucky.