> If the autostop valve has failed the cheapest (legal) option is to buy a ne=
> w
> tank set from gowesty.  (a replacement valve costs more than an entire new
> tank with the new type autostop valves.)

Whoa!  I replaced the Autostops on my two tanks with regular
fill-valves and bleeder valves--a setup that any propane
guy knows how to deal with.  (But the original problem may not
be the Autostop, but the non-Autostop-filler-guy who doesn't
know how to fill one....)

The fill-valve is about $30 and the little bleeder valve $6.
I had my local (excellent) RV guy do it, but here is
the same thing on the web:
http://www.dyersonline.com/merchant.mvc?Screen=CTGY&Category_Code=LP+Gas-LP+Gas+Parts

This spring I had both service valves replaced since it was very
difficult to get them tight enough to stop the propane.  They cost
me $22.95 each.  Better than the $48 on this web page!
A new Marshall regulator was $24.95 plus $3.25 for the white
plastic cover needed.

If the tank is rusty, clean it up and repaint it.

There is no reason to replace the tank; they are bomb-proof.  These
horizontal ASME tanks do not fall under the rules that forced the
replacement of all BBQ-style tanks.  Check the archives for
lots on this--the differences between horizontal and vertical
tanks and how/who rates them.  Or see:
http://www.sankey.ws/rvwinter.html

                        Richard A Jones
                        Boulder, Colorado