21" Essex Wheels

Kind HET folks,
My grandfather changed our 19E Roadster from 24" to 21" wheels a very, very long time ago.  I may have messed one of those wheels up trying to strip them.  Ok, full transparency here, I totally messed one up.  All the paint came off but I let it soak for too long and now as it is drying out, the spokes are shrinking, splitting, and cracking.  So, I need to check my stash first to see if I have another (it's 2 hours away in storage) but just in case there isn't one, I don't know what years the 21" wheels were used.  Can anyone help?  I see there is a rear 20" on ebay.  I am not sure if there were 20" wheels or it's an issue of where the measurement was taken.

Getting the car ready for the national show in July and there is a tremendous amount of work to be done!  Painting the body and doors tomorrow.

Thank you,
Ted Ringold
19E Roadster
19E Touring (24's on this car in case you are wondering)