I searched and cannot find measurements. A friend of mine is restoring (slowly…very slowly) an original TD. I could ask him. Let me know.
Or you might be able to make an educated guess by using these photos. One is of a dash parts diagram. The other is from a company that makes TD (and other) dashes out of a variety of woods. Just print the photo, measure it, and measure the proportions of the glove box door as they relate to the entire dash.
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster
If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)