Just wanted to let everybody know how this came out. One morning, I went out and put the vent window in a workbench vise. I used two thick pieces of rubber, one on each side of the glass so that the glass was sandwiched in between and the jaws of the vice were against the rubber. At first I placed the glass in the vice so that the frame was toward the bottom so that the lubricant would hopefully lay in the frame channel. Also, I left about 3/4 inch between the base of the vice and the frame so that there would be a little room for the frame to be lowered without hitting the bottom of the vice. Then I took a spray can of WD-40 with the little tube inserted in the spray nozzle and sprayed all around where the glass is inserted in the frame. I sprayed on both sides.
I left it sit like that until evening that same day. Then I took a screwdriver and hammer and began to tap on the very edge of the frame at both top and bottom. The vent window had a tendency to tilt in the vice as I struck it so I tightened the jaws some more and it didn't move anymore. I began to see the frame moving downward as I hit the the edges, top, then bottom and back again, over and over until I ran out of space between the frame and base of the vice. So, I unclamped the glass and turned the vent window upside down in the vice. But the frame had moved out enough there was actually plenty of room to place the screwdriver in between the frame and the glass. Now I aimed the hammer upwards to hit the screwdriver, still top end of the frame, then bottom over, and over and it started coming out more quickly as there was not much holding it anymore (only at a portion of the top and bottom).
Finally I could just pull upward on the frame and it came off the glass. Frame in-damaged and glass not broken. I was fearful that I would break the glass doing this, but the guy at the glass shop said he had the pattern for the '55 Ford vent window just in case I did break it.
BTW, I think I have an extra complete set of '55 Sedan/wagon vent window frames still attached to the window glass run/framework and whole nine yards if anybody here needs them, and there are a few additional vent window frames with good glass in them, but I think the handles are gone out of the frames. Let me know if you need any of this.