I don't know if this is of any use to you, 'cos I don't know if these cars are extant in your country, but on our '47 we used a BMC Austin/Morris 1800 wiper motor assembly. It gave us the 90 degree of sweep/arc for the blades, and also the "hand clapping" action of the originals. It was also cheap, very easy to fit, and we could utilise the original towers, so it still looks stock.

johnboy