As fitting vintage nibs to the Bock size 6 units on the regular-sized Bulkfillers is a relatively simple affair, how many FPN-ers have undertaken such a transplant? What did you install? How do you find them? Photos please! I'll start - Sheaffer Lady Lifetime EF nib on an FPR Bulkfiller demo. Pen filled with Sailor Jentle Oku Yama...