[1967 R50/2]

Originally posted by techweenie
29 years, actually.

http://history1900s.about.com/library/weekly/aa120700a.htm

No, actually Joeska's "60 years" is correct:

http://www.smh.com.au/news/World/Hidden-soliders-emerge-after-60-years/2005/05/27/1117129897877.html?oneclick=true

Of course, there may be other hold outs, but these two guys were well into their 80's...so if there are other hold outs, they may not be around much longer.