So they are there in the save folder you mean but they dont show when you load the game?
Is it possible they got moved or re-named?
In future you should make a back up everymonth or so. I goto my save file, make a 'copy' (NOT 'cut') and past it in a folder, something titled like 'start of spring year 4' or 'end of fall year 2'. I only do it at the start and end of every month (Usually day 27ish or 1)
I keep the freshest on on my desk top and to keep it organized I have another folder for all the old ones.