original floor mat

[Llay R. Rac]

somewhere around 1975 i put a cheap jc whitney carpet in my truck, i think i was trying to impress my gf , because back then i barely had money for gas.
in my memory i thought my floor mat was tattered and torn and brittle.
the carpet held up well but i'm going back to original, took out the carpet and was so surprised my memory was wrong.

the floor mat is intact and only has one small tear, which i made worse. what would i use to glue/stop this crack from expanding. The rubber is fairly pliable but feels a bit like dried marshmallows. you can see the tear on the right side of the pic.

heres a pic with a number on the back, not the best pic but it does show the general condition of the mat.