Without the ID plates it is no longer a Sandman unfortunately. Just a HQ Belmont van. Chassis number and engine number cannot be HQ Sandman but 4/74 certainly could be. Full length headling is not HQ Sandman. It does look like one, but there were heaps of those stripes around not fitted to Sandmans so could have been put on another one (it has stripes but no GTS guards). Looks like a trimatic badge on the LH side too but still could be a Sandman body.