I actually did know a guy in high school, around 1971, who was building a false identity, or at least claimed to be. No idea how that ever worked out for him — probably not well unless he learned to keep his mouth shut better.
I considered trying it myself but never did. That was about the last time the old get-a-birth-certificate-in-the-name-of-a-dead-infant scheme had a chance of working. With today’s databases and cross-referencing, I’d imagine the government could easily spot a fake identity that had been done that way even 50+ years ago.
The system worked like a charm until he was sent overseas to our base. There was only one bank on base, a credit union and check cashing facilities at the clubs and exchange. The base was small he should have shut it down. He had to bring in another person to cash the checks on base. You could cash a friend's check if they signed it, we did it all the time if we were too busy to make a bank run during the day. Apparently a teller or someone at Disbursing became suspicious when a Marine cashed a government check. Initially he was arrested on suspicion of stealing someone's check, It all unraveled from there. Had he not gotten greedy, we began direct deposit shortly after and he may never have been caught. Now the systems cross check everything and a false pay record would be flagged pretty quickly.