[quote=@Pathfinder]
[@caliban22]
Then how'd he live that long? Besides Chaos Marines, Bjorn the Fell-Handed, the living/Daemon Primarchs, and Belisarious Cowl, ain't nobody left alive from the Heresy that is/was aligned to the Imperium. Unless I'm missing some obscure character I don't know about or Bill here is a Perpetual.
[/quote]

Bar primrachs etc... Wait already listed. . There the only heresey veterans.thete may be some custodes, biological immortal but none confirmed. 
No marines bar born and my a technicality the 13th Space wolves company. 

Very short list I admit from that time on imperial side. 
No warp time shenanigans to help em.. 
Thigh with parts etc.... Nothing stopping a tech priest being -10k...