By looking up the part number at motogrid (1977) and the putting that number in the part search and lookind at all models you get the following
So the shoes fit all of the below list, which probably means the plate is from one of them
CB450 A MOTORCYCLE, JPN, VIN# CB450-1000001
CB450K1 A MOTORCYCLE, JPN, VIN# CB450-3000001 TO CB450-3008955
CB450K2 A MOTORCYCLE, JPN, VIN# CB450-3008956
CB450K3 A MOTORCYCLE, JPN, VIN# CB450-4000001
CB450K4 A MOTORCYCLE, JPN, VIN# CB450-4100001
CB450K5 A MOTORCYCLE, JPN, VIN# CB450-5000001 TO CB450-5040742
CB450K6 A MOTORCYCLE, JPN, VIN# CB450-6000001 TO CB450-6025991
CB450K7 A MOTORCYCLE, JPN, VIN# CB450-7000001 TO CB450-7022920
CB500 A MOTORCYCLE, JPN, VIN# CB500-1000001
CB500K1 A MOTORCYCLE, JPN, VIN# CB500-2000001
CB500K2 A MOTORCYCLE, JPN, VIN# CB500-2100001
CB500T A MOTORCYCLE, JPN, VIN# CB500T-1000001
CB500T A (76) MOTORCYCLE, JPN, VIN# CB500T-2000001
CB550 A MOTORCYCLE, JPN, VIN# CB550K-1000001
CB550F A MOTORCYCLE, JPN, VIN# CB550F-1109886
CB550F A (76) MOTORCYCLE, JPN, VIN# CB550F-2000003 TO CB550F-2010866
CB550F A (77) MOTORCYCLE, JPN, VIN# CB550F-2100001 TO CB550F-2114871
CB550K A (76) MOTORCYCLE, JPN, VIN# CB550K-1230001
CB550K A (77) MOTORCYCLE, JPN, VIN# CB550K-2000007 TO CB550K-2015308
CB550K A (78) MOTORCYCLE, JPN, VIN# CB550K-2100001 TO CB550K-2122082
CB550K1 A MOTORCYCLE, JPN, VIN# CB550K-1200001
CL450 A MOTORCYCLE, JPN, VIN# CL450-1000001
CL450K2 A MOTORCYCLE, JPN, VIN# CL450-1012469
CL450K3 A MOTORCYCLE, JPN, VIN# CL450-4000001
CL450K4 A MOTORCYCLE, JPN, VIN# CL450-4100001
CL450K5 A MOTORCYCLE, JPN, VIN# CL450-5000001 TO CL450-5019216
CL450K6 A MOTORCYCLE, JPN, VIN# CL450-6000001 TO CL450-6005014
