i have reclaimed head by various methods , but would be seriously sceptical about having the face completely welded and re machined simply because of hardness issues
thats not to say it cannot be done , karl, you must have done this succesfully otherwise you wouldnt mention it , just one of those things i wouldnt have done till id tested it myself
though i must admit ive rewelded stuff and machined it back to good as new that alot of people said was scrap