KO, is this a canoe you have bought, or are thinking of buying?
Grumman made three different kinds of keel, as shown in the brochure in Benson's link. The most common ("standard") has a T-shaped cross section, essentially it's a long skinny fin extending about 1-1/2" below the bottom of the canoe.
Grumman also made a shallow draft or "shoe" intended for river use. It's a shallow D-shaped cross section perhaps 1/2 to 3/4" below the boat's bottom.
The sailing rig could be fitted to hulls with either keel. I've never seen a Grumman with the bulb keel, but AFAIK it could also accommodate the sailing rig.
The leeboards are mounted on a separate thwart that can be clamped to the gunwales. In theory it can be moved fore or aft to achieve a balanced helm. With all the sailing parts in place, there is not much room for a passenger.
There were also two different size sails. The 1975 brochure shows only the 44 sq. ft. lateen sail. There was also a 65 sq. ft. sliding gunter; perhaps it was discontinued by 1975.
The Voice of Experience says that 65 sq. ft. of sail on a skinny canoe hull makes for a tippy boat. Sailing this rig is not for the faint of heart.
I removed the sailing thwart from my Grumman for general river use. IMO it would make it difficult for the bow paddler to bail out in the event of a capsize. This thwart was attached with stainless steel screws. After 40+ years of galvanic corrosion, I had to destroy those screws to remove them.
My Grumman also came with a cam cleat to hold the main sheet while sailing. I removed that as well. Belaying the sheet on such a tender and over-canvassed boat is a bad idea.