they are called pre bent levers , maybe the 1st dia compe BMX lever so although i have never heard them called this a Tech 1,although i would imagine the first was not bent
a few diff types of pre bents were made this one is a 45 degree one
and looking at the code on the inner bit of the clamp it was made in 1981
and the odd colour clamp was factory , but i have only ever seen them from the USA with the odd colour clamps so maybe this one was bought from there originally
god i need to get out more lol