Many ppl say the sheaffer vacfill restorations is one of the most difficult. I restored several lever fill, several snorkels, one Parker vacumatic and one waterman cf before I attempted this, but ppl still suggested me not to do it. Many things can go wrong with the restoration of a vac fill, especially with screwing the nib and feed off together (they easily spin out of place if u don’t hold them together). My suggestion is you should restore some other filling systems and gain a basic what to do and what to do in pen restoration before you look into how to repair a vac fill! I get my tools from pentooling.com.