I've been told the Firebird uses the same lenses as the Parisienne.
My lenses print show GUIDE 25 SAE DP 67 but a photo on Classic Industries for the Firebird shows GUIDE 22 SAE DP 67. Antique Chevrolet claims they are the same. Visually they look the same, but are they?
I think this has been discussed before, and if I recall it was found while the Firebird and B body lenses are actually the same size & fit, the design of the reflector inside was different.
Check for different text on Canadian vs American lenses
On my 65 Impala the lenses differ in that way with the assembly line and NOS Canadian lenses I have