MAC valves... rebuild?

i have some of the blue mac 3/8" valves. the big ones where each valve controls both up and down. i was wondering if anybody knows where i can get a rebuild kit or a diagram to take them apart and clean them out.

i got these from cool cars about 3 years ago, the valves are really slow, but the last time i had them on a vehicle i hade one that would stick up and one that would stick down. before that i had no problems with them at all.

any help would be appreciated, since i already have these valves it would be nice to be able to use them on a mild project i have in the near future.

thanks,dan

i used to have those and when they would stick id just hit all the openings w wd-40