How do you tell the speed of down tube shifters

I have some down tube shifters which are Campag Chorus and from looking on Velobase they were made as either 6,7 or 8 speed and were synchro or friction I think. They were on a bike with an 8 speed cassette and did not shift correctly all the time which led me to think that the shifters and cassette were not matched.
My query is by looking at the shifters, how can you tell which speed they are?
Thanks

Take them apart and count the notches in the toothed wheel?

Search for "tears for gears": he's a Syncro fan and you might find something there.

Take them apart and count the notches in the toothed wheel?

^Not sure if serious...

@SideshowBob put them on a boss (or jam a big allen key etc in there), click them through their range of movement, count the clicks, add one and you've got your answer.

Ha!

Same principal as your suggestion, but i assumed he didn't have access to a frame as that's the obvious thing to do. Didn't think of the Allen key trick though.

Actually now I've dug out the TFG article, the colour of the insert might tell you what speed they are.

If they are they can be used on friction setting then it does not matter. Always prefered friction D/T shifters over indexed ones as I can run 10 speed on the cheap.

Always prefered friction D/T shifters over indexed ones...

Likewise.

I can (could) shift much more quickly with (retro-)friction shifters and their simplicity has it's own appeal.