Tudor Big Block 9430/0 "Floating Chrono" Information

[zerocool]

Hello all,

I've been researching the Tudor Big Block 9430/0 and it would seem that the earliest version with serials dating them to around 1976, did not come with the "Automatic - Chrono Time" inscription surrounding the 6 o'clock hour counter. These apparently early versions only have the inscription "Chrono Time" under the Tudor inscription.

I've come across a listing calling them "Floating Chrono" Big Blocks. I'd love to know if anyone has any information about them and for how long they were produced. I've only been able to find a handful after a long while of researching.

I'm attaching a picture for reference.