Lens Repair Options

[Joseph Tainter]

As I posted a short while ago, I just picked up a battered F* 300 f4.5 
that needs repairs. Aperture works fine, optics look very clear. The 
barrel appears to be in two parts, which are joined underneath the 
autofocus/manual focus adjustment ring. The body is loose here and 
wobbles quite a bit. Other than that I think the lens is okay, but I 
will be testing it today against some others.

Need advice: Should I eat the extra cost of sending this to Pentax USA, 
or would KEH be okay for repairs? Or does anyone recommend another 
source? As long as the lens is being taken apart, I figure I may as well 
have them give it a thorough workup, whatever that consists of.

Can Pentax bench-test it to see if the optics are performing as they should?
KEH's online quote system is telling me $35.00, which sounds 
suspiciously low.

Thanks, everyone.
Joe