(Login GMTKiwi) VRF Member Posted Jun 27, 2012 4:18 PM
In 1970 a Twinlock was probably the go for a 5512 but a Triplock is a very sensible improvement.
Here's some Triplock history courtesy of Philip a couple of years back .....
Rolex Oyster Triplock crown (and tube)
701 was (officially) born in 1971,
on january 1972 all AD's received a Rolex memo
mentioning that 5512/13 1680 1665 6263 6265
as well as Tudor 7016 7021 7031 7032 7149 7159
and 7169 would receive this 701 Triplock 7.00mm