Can anyone recognise this?

[Mary Lindsay]

Hi,
Here are some pictures of one of a pair of brake master cylinders fitted to a mid-1970s single-seater home made aircraft. Can anyone identify its origins (motorbike, perhaps)?
It bears no makers name, just instructions on the reservoir lid (in both English and French) to use Dot 3 brake fluid. I need to locate some replacement seals.

[Barry Sumner]

Definitely motor cycle – will put my thinking cap on

[Colin Musgrove]

Looks a bit like a Beringer with the lever cut off, try here : http://www.frogspecialties.com/index.php?categoryid=56

Loads of bikes have them now, but they didn't in the 60's and 70's. I should try Googling and check out some of the Forums

Colin.