63 Dodge Dart, now let me see;)

ok, switched gears a little, too hot for me to work where the Dart is, so playing in my air conditioned garage;)
I've cleaned up the side plate on my A833, put new o-rings on 1/2, 3/4, but the reverse lever, do I have to pull the tail housing off to get the reverse o-ring?

I've had this motorcycle stand seems like forever, works well for what I'm using it for.
A833 stuffb.jpg

So, the question was/is, to replace o-ring, does the tailshaft have to come off?
A833 stuffa.jpg

Blasted these, but won't be using this shifter plate.
A833 stuff.jpg