If you going for the right year combination for the 77 and an Oliver baler, the following balers would look good:
Model 18 1949-51 (wire tie heavy almost impossible to find and parts will be almost impossible to find)
Model 100 1953-58 ( same problems as the 18
Model 50 1954-57 (twine tie, lighter, maybe easier to find, parts still a problem)
You can see these balers in C.H. Wendel&#039;s book OLIVER HART-PARR.
If you are interested in baling large quantities of hay, I recommend getting a much newer baler produced after Oliver quit building balers.