If these came from a box of old bits, they may well have been bar end shifters as used on road and CX. They sit it the end of the bars so shifting on the drops I=s easy. They will be friction and could be used with 5 speed upwards. The exploded diagram shown earlier in the thread looks like a down tube lever, a bit different from bar end!
At one time they were extensively used on the road, sprinters liked them as you could slam the lever into top with 200 to go and hope it all worked...!
The real home was CX, where all the top blokes used them, this before the days of indexing, when men were men, etc...(cont'd P.94)