My build 63 gmc 4x4 Beastine!!

[Matt's k5]

picked this truck up over a year ago, 305 v6 factory 4x4 it sat for many years, it used to have a short bed step side on it just wired on from the farmer, my question is did the make these trucks without bed mounts?, there is one set of mounts but it's is bolted on not riveted this pictures showing no mounts there is not even holes on frame for bed mounts, also found there is no shock perches on the rear axle, it looks original would like to see other truck frames like mine, any input from you guys is appecatied more pics to come!