Sorry, I couldn't remove this. I'll have to ask a guy friend to do that for me & help with installing a replacement.
I did measure it. The gap that holds the rail & the rail itself is 1" 2/8ths wide. In total, from top to bottom it is 1" 1/2 long.
1/2" is the area holding the rail, below the drawer. The furniture is from the mid 1970's.
Thanks for your help, Kate