I tried it at a very low idle as well as higher RPM. No go, but then I didn't know the trick of reversing the control. I just found a video on You Tube about the same issue on a CASE 580K backhoe.
It shows the guy reversing the control at the last minute to latch the lock, although the lock is a different design. I went out to try it after I saw the responses to my post. It had just finished raining and the mosquitos were vicious. I came back in the house and will try again tomorrow. I did notice one thing, however. A bird got inside the cab somehow and splashed white sh** all over the seats and engine. I have the doghouse removed so the bird must have gotten in that way.