Hi Olof,
Those are Campy Sport Cranks. They appear in the #17 Campy catalog, and are under the Gran Sport Group. The 150 arms are for juveniles, and are rare, but not a lot demand for them either. These were Campy's low end cranks, and not very desirable amongst most collectors.
Marc Boral
Olof Stroh wrote:
> Newbie to the list I will come back with a short - very short - introduction.
> Found this list when I posted to questions to the bob list and was directed
> hither. First one - made actual by the ongoing Campa crank thread - is:
>
> Rummaging a small Stockholm bikeshop couple of weeks ago I found
> some peculiar Campagnolo cranksets. They look in style like old
> Nouvo Record, fluted and milled, but with three pins to hold the
> chain-wheels instead of five and stamped with Campagnolo Strada
> on the backside. Two sets were just 150mms ( and hadn´t my
> children bee too old they would have got something very cute )
> with double chain-wheels, 45x38 and 42x36: these had normal
> NR bolts. Two were 170mms for singles, one - that I bought
> cheap - with just a 36(!)chainwheel, one with an adapter for a double,
> those had non-countersunk bolts. Bcd - as I measured with a ruler -
> is 115mm except those on the adapter who are bigger, but still 3-pin.
>
> What is this? Someone knowledgeable, please explain.
>
> Dangerous thing, bike shops.
>
> Olof Stroh
> Uppsala Sweden