The guy you are responding to said Tesla, you changed the subject to another company elon owns. Tesla losing value would be extremely harmful to elon. The guy you responded to knew what he was talking about. You are just adding noise showing that you know of other companies elon owns.
By my calculations, the most backwards-compatible thing is probably going to be booze. Booze in 1941 and now are pretty much the same thing with minor superficial differences. So I would send all of Camp Pendleton back to 41. Nailed it.
Put some planes without clothes on it