Proper installation of paper element for air filter N15

Hi
I have a wedge shaped air filter housing from Walridge to fit up to this N15 with Amal Concentrics. It came with pleated paper element.
Trying to figure out how to fit the paper element into the wedge shaped housing. The narrow end of the wedge is smaller than the folds of the element, which means you have to unfold the filter some but at the top there is nothing to anchor it.

My Atlas has a filter element that is not paper, but a course foam type stuff.

Any ideas?

Thanks

My G15 had a wire encased filter element that obviously was originally oil-soaked but completely perished.

I bought a slightly larger, similarly-constructed K+N filter with a rubber perimeter and cut the rubber off, then trimmed it to match the original, then sprayed it with WD40 and slid it into the wedge.

I think I paid about $20 for the K+N.