The runner issue is easy to fix:

http://www.woodpeck.com/incramiterslide.html#52

On 8/19/2010 1:44 PM, RicodJour wrote:

Time to rebuild and buy adjustable runners.

HDPE. The **** is the...errr...**** for runners. Stable, easy to
work, slides like greased snot and it won't bark if you accidentally
drop the sled in your bathtub. The MDF is another matter.

R