shower door sweep

Basically, I am looking to replace the rubber (round top) shower door bottom sweep piece that slides into the shower rail attached to my swinging shower door. Does that make sense? The problem is my shower door is extra-wide as I believe it was built to be wheelchair-accessible. Most sweep replacements are 36" wide while I would need something 39.5" wide (or larger and I could cut it down). The rubber sweep piece that is on there now is older and worn so water is leaking from the shower to the bathroom floor. Please let me know if I can provide additional information or additional photos. The photo labeled INSIDE SHOWER SWEEP shows the piece I need pulled out a little. It's a clear (but not very clean or nice anymore) rubber piece. Also, the size of that rubber piece lengthwise is 36" + someone cut another piece to make up for the additional 3.5" and the height of it is 3/4".
Thank you
Christina

Hi Paul,
Thanks for the fast response. 37" would fall short of the 39.5." I think the best bet is for me to buy TWO 37" (or actually two shorter sweeps) and epoxy them at the seam to create 39.5" long sweep. Do you recommend a special type of epoxy or will anything do (including rubber cement)?