Well Hikerdogs...I acted too fast
. You're right on the money.
I took the whole resevoir off (breaking rusted bolts in the process) thinking that it was a sealed, all in one, unit. After reading your post, I stuck a socket in the resevoir and simply unscrewed the intake filter (nut shaped) on the inside of the resevoir from them pump on the outside and it all came apart nicely. Had I left the resevoir on the coach I could have made this an easy task. Now I have to drill out the rusted bolts and remount the resevoir. Alas. Not a big job but harder than it needed to be.
On edit: The pump is not a Ford product and some pretty good auto parts stores here could not come close. Mobility RV, the Winnie parts people, had it (comes as the resevoir and pump all in one) for about $35. It's on order.
I report all this so that it'll be in the archives for future reference.