The ecentric pins are the "bolts" that you loosen to adjust the rims.
The .625" square by 1.75" long parts with the diagonal notch are the wheel lock breaks. When I just redid my MF65 pow. adj. wheel last month, I did not realize those were in there and lost two of them.
There was a kind spare parts dealer (MF dealer)in Kansas who would gladly sell them to me for $68.00 each. There was another who felt these little gems were gems and wanted $25.00 each (mind you there are 8 on a tractor).
Bluck"s was most reasonible and had them for $14.00 each.
I wanted them sooner than I could get up there or shipping allowed so I got a couple of 1/2" keyway stock pieces from the hardware for $2.00 and spent 45 min one evening with a half-round file and made them.