So back before I bought my Sport Cub, I spent a year getting the Grove wheels and brakes approved on my Champ.
When I got my Sport Cub I couldn't believe the hydraulic reservoir. Taking out the cap was a pain and it was already pretty deformed when I bought N5058.
My husband talked with Grove and we converted both our Sport Cubs to the same reservoir that came with my Champ's kit. PN 067-0850 Reservoir Assy. A 1/8 inch x 1 1/2 inch nipple as a standoff to not interfere with the rudder pedals and we now have reservoirs that are easy to refill and hold more fluid.