[Buffalo]

Unless they have changed the way the larch works on the 2013 from the earlier models it is a fairly simple affair. Spring loaded arms on the latch just snap into notches on the bars of the buttstop to lock it into the position you want.

Does the latch on your move into the closed position when the buttstop is totally removed. If so then the only thing that I can think of that would prevent it from doing so with the buttstop inserted is that the notches in the bars are not lining up with the arms on the latch. Try sliding the stop slowly forward and see if it will lock in at a slightly forward position. If it does then something on your conversion is keeping it from lining up in the fully inserted position.

 

[Buffalo]

Does sound like something in the latch is jamming. Since I have never seen how the latch is set up on the 2113 I can't tell you for sure what you will have to do to fix it.

You might try looking in through the holes the arms slide into to see if you can tell what is binding it. If yours is like the earlier ones, there are two screws under the seat that screw through it into the latch and secure the latch. You might try loosening those just a little and moving the latch around to see if that will free it up. Do not completely remove them though as it's bear to try to get them reinserted into the latch.