I understand the need to effectively use what is available, but have you entertained the idea of getting a new file drawer system?
By new, I mean replace it with one that "works" properly. I had the same dilemma, I was using some 30-buck cheapies that I converted to a pendaflex system. it was squeaky and cheap and felt like I spent 30 bucks. After reading GTD, David's comments about the file drawer rang true, similiar to the use of a good labeler.
But I'm a cheap guy, so off I went to the Nice but Used office furniture store. I literally hunted around the place for an hour and then I found it.
A 4-drawer Steelcase.
It was institutional metallic green. but the drawers rolled as if they were on air. The ball bearings were all there and bigger than my kid's marbles. I never saw them on them HONS or anything NEW at staples or Office max. It weighed a ton and had no dents or warps, just some scratches. And it was at least 30 years old.
It made it to my basement and the back stops all work. A bit of synthetic bike lube made it perfect.
Best 100 bucks I've spent yet.
The old ones hold the manuals in the wokshop, old (stored) financial records. And the worst one became part of the recycling heap.