Ok, Hello Everyone. I am new to this forum and to vintage fountain pen restoration so if I am in the wrong forum please advise. I have recently found a Watermans pen which I have identified (I think I have anyway) as a Crusader made between 1948 and 53. It needs a new sac and I wondered if someone could help me with a size and some suggestion of where you all buy them and shellac etc. Also, have I lost my mind as I get into yet another hobby/addiction? Thank you. JWC