MacClean softener

I have a MacClean softener and filter. I just changed the media in the filter and decided I should change the media in the softener as well. It's 25+ years old and never changed. It's a CS1500 and I can find no where on the Net regarding the type of media to use. Actually nothing about MacClean at all, even Cuno has no info. I know it takes 1.5 Cubic feet. Does anyone know what type?

Standard softener resin ,(cation exchange)
Nothing special about the resin.
Purolite - hicap or c-100x10
Sybron - C249
Resintech - CGS or CG10
Any of the above will work for your system.

Thanks for the prompt answer!