The tiny lettering below "The Vette Shop" MIGHT be "MOUNT CLEMENS." That would be logical because it would be the same city as MPC's offices on the east side of Detroit.
If true, these links suggest that a "Vette Shop" was there:
"I live on the eastside of Detroit (MT Clemens)... The Vette Shop on Gratiot has closed." 2005. https://www.corvetteforum.com/forums/great-lakes/1068861-east-side-of-detroit-need-service.html
"The Vette Shop address is 33376 Kelly Rd, Clinton Twp, MI 48035, USA." Undated. Clinton Township is just south of Mt. Clemens, MI. https://www.helpmecovid.com/us/location/4208578_the-vette-shop
"The Vette Shop used to be Windy's Bar in the 50's at Gratiot and Melvin on the N.W.corner." 2017. https://www.facebook.com/groups/988004691265148/posts/1336741149724832/