Defiling a track frame for road use by drilling for a fork is defiling it far less than riding it on the road without a front brake or a possibly inadequate one (the clamp-on). I know a mechanic who specialized in fix gears. People bring some gorgeous bikes into him to work on. If it is a brakeless bike ridden on the road, he does his best to completely remain aloof from the bike. Doesn't matter how gorgeous or special it is. He used to have for sale the very best Japanese keirin bikes. I watched him work on a customer's brakeless bike of that genre. Asked him about it. Told me it hurts him so much to see a bike that is going to get destroyed that he cannot pay attention to any part of it he isn't actually working on.

If you brought that same bike in to him for a drilling for a front brake, he would do his best to make that drilling perfect. So you could put a beautiful SS bolt in and ride it brakeless as intended when you took it back to the track.

Ben