Prodelin 6' on C-band?
Around
post #121,
Linuxman and
Pendragon came to a meeting of the minds as to where the focal point is for that dish.
You might use that thread for encouragement.
Now, there's a similar-looking dish, with three support arms, which is claimed to be ChannelMaster, not Prodelin.
I don't have either, so can't argue the merits one way or the other.
Post some pictures of yours.
As for LNBF's, some guys seem to like the 421.
I intended to use the SatAV CK-1, but the dish disappeared and I never got it.
I'm kind of holding my breath to see if anyone fires up with the CK-1, and makes any great claims for both bands. -

Linuxman seems to be getting good Ku signals on his dish with regular Ku LNBs.
I've also bought the C-only, B1-stacked Eagle Aspen from Sadoun.
Just depends if you want to run bandstacked to multiple receivers or not.
Someone posted a link/picture/PDF of the original mount for that dish.
It takes a jack to move it.
Problem, you get the dish for nuttin' , and then pay $200/300 for a mount?
I don't think so.
As a fixed dish for Puerto Rico @ 99°w C-band, it should likely work fine.
But for C-band, it should probably have a conical scalar ring.
There's been plenty of discussion on using an offset dish for C, so you should find lots of info.
If not, we can dig up something for you if you have specific questions.