To be fair, I think Geezer is right about a well fitted and fettled loading tap being a wonderful thing... however, I've used a lot more bad ones than wonderfully good ones. And with modern production methods being what they are (more automation - less skilled human involvement), I wonder if a new tap-loader would be viable... is it possible with modern machinery/materials? Or is it just too tricky to get the thing perfectly sealed and aligned every time...?
Your Mod. 50 sounds like an interesting project, Ali.