Hi Frank,
I own a later production CLW Kit that could be adapted to a GP38/GP38-2/GP40/GP40-2 with the included parts and depending on the CLW Blomberg type of Trucks obtained.
I wonder if they made an earlier GP-40 Kit as shown in your posted pic and a later "generic" EMD GP kit that could be adapted to different GP-38/40 model types...
Regards, Steve