I've been looking at file guides the past few weeks and decided it is something I could use. I saw one by Bruce Bump and another from Uncle Al. These use carbide steel guides and should last a life time. The cost is also reflective of that. $100-$150.
Well, I did a little search and was lucky enough to find two pieces of carbide steel on the auction site that measured 3/8"x1/4"x3" for $12 each free shipping. I'm not a machinist but I was able to make some bases out of some phenolic chunks leftover from bow risers. I used jb chemweld to hold the carbide strips in place. We'll see how long it holds together. So far, so good!