[morzh]

RF is not involved here in the 46 case. And actually in the case of another Philco a triple electyrolytic was used (forgot which - maybe 18, that I restored). These are low pass filters or decoupling and electrolytics are quite good at it.

Any cap will do. Of course at these capacitances iy may be easier to find film ones, buit they are quite large and el'ectrolytics will be much smaller. I would use them.