I've been looking for a Miche 9 speed 12-25 cassette witgh no joy.

I currently have a Campag spacing compatible Miche 9 speed 12-23 cassette on my bike.
The wheel hub is a Miche and the freewheel maybe integrated making it a Miche freehub?.
Of the freewheel spline locators for the cassette there is one large gap and onse spall gap. The top of one spline has a groove in it. My current cassette can only be fitted at a precise location on the freehub splines.

Please can anyone suggest a UK source for a Miche 12-25 cassette that will fit on the Miche freehub.

I will post photos of the components if that helps.

Thanks in advance