http://www.oldgmctrucks.com/page0010.html

Here is an ignorant attempt to decode (using a USA-codes interpretation):

152 24 P Z5035

15 = 3/4 ton
2 = 125.25' wheelbase
24 = 248 engine
P = Pontiac
Z = Z-series = 1954/55 New Design truck

5035 = 5035-1000 = 4035th 3/4 ton truck out of that plant (in that year or in that Z series of years).