This is the curse of restoration when "flying" somewhat blind. i.e., without good source-drawings or photos to study. I found when I did my TE, I did many things twice. And there was no common-cause. Sometimes poor machining on my part, or the job did not look right; or, as we discovered later, it was to foul some as-not-yet-thought-about part. My solution, as with all conundrums of this type, lies with Doctor Shepherd & Dr Neame's patent problem-solving elixir - to wit, Masterbrew.