SHFNI Rotractrule

[seafuryfan]

My SHFNI Rotractrule is becoming somewhat dog-eared. Even fablon can't save it. It's a great piece of kit, fits in a flying suit.....
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1500x2000/shfni_rotractarule_582ce288dba163c2aed1e884954ccd3490ee4287. jpg
Does anyone have one in their memorabilia collection they'd be willing to trade or let go of? Thanks.

[ShyTorque]

Obviously a Wessex one because it only goes up to 120 kts! :p

[Shackman]

Shame you didn't post that about two weeks ago - just had a big clearout!

[India Four Two]

Fascinating device. When I looked it up on Google, my quest was self-referential, back to this post!

Some questions:

Where does the name come from?

What was the graph used for?

Who produced 1:20,000 maps? I would have expected 1:25,000.

PS I know what SHFNI means. It's the other bit! :)