Jerry, if I'm looking at your photo correctly, the 51107 has sort of a rounded "dome" on top - is that right?
The 51010 does not look like your 51107. (Just so I'm clear - the 51107 filter in your picture is one you purchased new, and just recently installed? Was it old stock? The holes look completely different that the 51010.)
The 51010 is about 4.25 inches tall, and 3.75 inches in diameter.
On each end, there is a raised metal circle (same metal as the body of the filter), about 1/8" tall, and 1.25 inches in diameter. (Like a bulls-eye, in the center of the top and bottom.)
There's a hole, a little over a half-inch in diameter, in the center of that raised area on each end. You can feel the edge of a rubber seal, when you put your finger in the hole.
The Baldwin P40 is the same size as the WIX 51010, but the "raised area" on each end is smaller, and made of rubber.
In other words, when you set both filters down on their bottom, the WIX is sitting on metal, and the Baldwin is sitting on rubber.
If the filter needs to seal on the ends, it looks like the Baldwin will work better than the WIX.
I'll try to post some pictures.
A while back, I went to the Fram website, and got a list of "Competitor Cross References" to the Fram C153, which should be the "right" filter for the TO-20.
As near as I can tell, all of the filters Fram's list, including the WIX 51107, have been discontinued. (Fram even cross-references back to the Ferguson TO-18662-2 number, which is the part number for the oil filter in the original TO-20 manual!)
Keep in mind: I have NOT taken the filter out of my TO-20 yet, so I have no idea what I'll find in there. You're much better off listening to Jason, who has actual experience!