I use those EZE-Diamond Lap sticks quite frequently.
For this job I first use one to flatten the bottom of the frizzen. Make it as highly polished as you care to do.
But keep it FLAT. The more you go at it, the better the chances of starting to round it slightly.
Put the frizzen back into the lock assembly with the frizzen spring in place.
As Smartdog points out, this will make sure the frizzen is pushed down where it will always go with the spring tension behind it. Something you can't really duplicate by just running it back and forth by hand w/o the spring in place.
Brighten up the top surface of the pan edges and then smoke them with a candle, smoke lamp or what ever special method you like.
Using something like stock inletting black or similar marking substance will give impressions of high spots but generally much too oversize in nature for this type of close fit work.
Snap the frizzen closed and open and check the high spot 'in the white marks. They may be tiny in some instances or very bold.
In cutting/clearing them down, use a simple scraper instead of a file.
A file digs in too much when trying to get just a small specific spot..
A scraper will cut fine curls of steel from just the right spots very easily.
Nothing more than what you use for a small wood inletting/carving tool scraper works very well.
Pull it towards you.
A right angle hook scraper with a flat edge blade of very narrow width will allow careful and easy removal of the soft metal at a fast rate.
Re-smoke the surface and keep scraping till full contact is achived,,or as near as you can get.
A simple quick polish over the scraped surface with a fine grit diamond lap when done will blend in the scrape marks (which may be in different directions) and keep the surface flat and perfect contact with the frizzen.
