915 trans odd problem
 

I have a 915 trans that supposedly has 60k miles on it and was removed from the car in 1990 in good working condition and put up on a shelf where it sat until now ... the shifter rod is able to be moved and select gears but when in neutral position and you turn the axle flanges the input shaft turns and you can not hold the input shaft from turning it is still engaged in a gear ...second gear I believe, select any other gear
and the axle flanges are very hard to turn together like binding or like the box is in two gears at the same time ... Is that possible?
Any ideas appreciated...
Thanks
Tony