Vintage down tube Simplex gear levers

[bagpuss]

A friend gave me a pair of white plastic Simplex D/T double gear levers . My guess in they are from the 1970's .
Not found any info on the net .
They very light . Anyone know what range of Simplex they are from .
Thanks in advance .
Pics to follows .

 

[mdvineng]

https://velobase.com/ViewComponent.aspx?ID=18B3526D-6AF1-4216-9E39-535A92E5B649&Enum=104&AbsPos=242

 

[bagpuss]

Thank you for the link.
Mine have a metal clip with white plastic levers . I bet the original clip had snapped

 

[Old Ned]

Could be from the Prestige mechs. There were two versions at least. The first were all plastic in a sort of geometric shape - they snapped. The second were more 'normal' with a metal clip. Your piccies should confirm.

 

[bagpuss]

Said levers