Once they got past the eyedropper filler stage and lever fillers came along, that’s what Conway Stewart did, with huge success. I’m talking about the original company, of course, not the various later efforts that borrowed the name but little of the enterprise.
When something works there is no point in messing with it, and Conway Stewart’s lever fillers worked well with the same – rather good – design for decades. Like Waterman they used a slide pressure bar which depresses the sac much more efficiently than the J-bar that some other manufacturers used.
Despite that great success, Conway Stewart did try other filling methods. The Speedy Phil was a complicated twist filler. There are a few around today but it seems clear that they didn’t sell all that well. Conway Stewart also made a first-class button filler, but again, the numbers surviving suggest that sales were poor. It looked like the public was telling Conway Stewart to stick with what they did best: lever fillers.
They tried one other innovation, the Ink Visible, a type of piston filler. I’ve wanted to get my hands on one of these for a long time but they don’t turn up very often. Again it may be that sales were low, but in addition they are quite fragile, and any attempt to disassemble one has to be done in the right way and with appropriate caution.
I managed to snag one in eBay recently. It had been in good order before someone started fiddling with it, pulling the nib and feed partially out and leaving tool marks. Checking visually, it doesn’t seem that the tamperer has managed to break it.
I plan to leave restoration for a time when I have nothing to distract me. I would really like to have this pen back in working condition again but I know it won’t be easy. I’m not going to be too strictly original about it and I can see the cork seal being replaced with an ‘o’-ring. The pen has a nice oblique stub and I’m looking forward to using it. More will follow!