Flail Mower MF 6' flail mower question.

[aczlan]

while we are talking about flail mowers, I looked at a MF 6' 3 point flail mower last week it looks like it has been around the block a time or two, it was hooked up to a tired 8/9N and it sort of shuddered/vibrated at low RPMs but was smooth at high RPMs.
the PTO output shaft on the tractor looked like it might have been wobbling at low speeds but I couldent tell.

there were 4 flails missing of the ~120 on the bar.

any ideas of what would cause the wobbling, and should I buy it (price is under $900)???

Thanks

Aaron Z