I recall this year's convention had a presentation on the W-L, here's a neat article from Popular Science: http://books.google.com/books?id=qiEDAAAAMBAJ&lpg=RA1-PA225&ots=VMiQkD88Ru&dq=metal%20shell%20picture%20tube&pg=PP1#v=onepage&q=metal%20shell%20picture%20tube&f=false