Here is a link to the Sport Coupe pieces.
https://www.ebay.com/itm/1928-1931-M...ty!78205!US!-1
You can tell they are different.
I don't know what the Cabriotets have. The whole Bow folds back since the landau bars actually work on them. There are three different set ups depending on the year for them
I don't know if other companies made similar models or not. They may be wood braces for some other open car too.