I collected 'Flighters', the all stainless Parkers for a while. From left, 25BP, 25, 45(?)FT,45, 51 (holy grail for me), 180 (two nibs XF/M in one pen), Sonnet, Sonnet.
It's fun and you can build a collection pretty cheap. I stopped after I bought a Shaeffer Snorkel, realized it was quit or no turning back. How well does that 'Hero' write, Gary?