Is the arrowhead shaped bracket pointed up or down or? If you have a 40 Chevy, please take a look.
This is the style department of Chevrolet at work. Every Chevy from the 40s I've ever seen the arrow head points up and back.
I just looked at my parts master. The shade is Group 10.203 - the support is Group 10.219. All closed 37-40 use the same support. All closed 41-48 use the same support - except wagons and fastbacks - and of course the convertible is different too.
The part numbers for shades changed every year - but this is likely because of minor style/fabric changes. Dimensions are dictated by the support - so my gut says they'll likely interchange.
If it were me I would order a set from Chev's of the 40's and see if they just might not work. '41 was a new body. Is the interior space wider then the 40? If so the sunshades might be longer then your support. But they still might work. Or your upholstery guy could tweak them.
Happy hunting and good luck.