Vintage Pens are Hard to Buy
The many wonderful vendors who serve the modern pen community have spoiled us. They provide extensive information, detailed photos, and customer reviews about their products. Many of their websites are lovely. In contrast, Dr. Deans has compared the sites of some vintage vendors to Soviet prison camps. A little harsh, but many have at least a hint of the late '90s about them. Many vintage vendors are small (sometimes one-person) shops. They may not have professional photographers, web designers, or data-entry minions.
It might help to think of your transactions with vintage pen dealers as more like ordering a custom pen from Edison Pens or Shawn Newton than like ordering the latest TWSBI from Goulet Pens. It might take a few emails to secure the sale, but that gives you a chance to ask questions and engage with a fountain pen expert!
Keeping one's stock up-to-date on a website is a time-consuming task, especially when every item is unique. Vintage vendors may have items that aren't currently listed. If you tell a vendor what you're looking for, they can often oblige, even if the item isn't listed on their site. (That said, don't go asking vintage sellers about items outside their usual range of interest. It does no good to inquire about a vintage Pelikan from a vendor whose site clearly indicates a specialization in American pens.)
I've spoken so far about obtaining pens from specialist vendors, which is by far the safest way to go. The second best way is through non-vendor ads on the various fountain pen forums. My experience buying from the forums has been very good. Read the descriptions carefully, examine the photos, use common sense, and you'll probably have a good experience.
The final way to find a vintage pen is through online auction sites. This is a far riskier way to buy a pen. Personally, I only buy pens from online auction sites if the seller is a fountain pen specialist. Auction sites are filled with "I found this in mama's attic" ads and you should avoid those. A red flag is that non-pen-dealers on auction sites seem to describe everything as "rare," despite the fact that there are dozens of that model listed for sale. If the seller thinks a Pelikan 120 is "rare," then you don't want to buy from them.
At this point I'll mention a price factor that I omitted above: the reputation of the vendor. Other factors being equal, you may pay more for a pen from a reputable vintage dealer than from an auction site or a random ad on FPN. Personally, I regard the extra cost as a good investment. Specialist vintage dealers have reputations to protect and do not want unhappy customers. They have extensive knowledge of vintage pens and restoration methods. Sometimes they will even offer limited warranties. Going after the "too good to be true" deal from an unknown seller on an auction site is a recipe for disappointment.
Vintage Pens have Freaky Filling Mechanisms
Over the decades, there has been a winnowing of filling mechanisms. Most modern pens are either piston fillers or cartridge/converter pens. There has been a recent revival of interest in vacuum fillers (e.g., Pilot and TWSBI) and Edison Pens produces modern versions of the classic pump filler and pneumatic mechanisms.
In Days of Yore, there were far more filling systems and companies competed in developing mechanisms that maximized ink capacity and minimized mess. Many of these systems are based around a "sac" or "bladder," a flexible ink container inside the pen. If you've ever used a squeeze converter from Pilot or Kaweco, you get the idea. Several filling systems used such an internal sac and were named for whatever mechanism was used to compress and expand that sac, but they're just variations on the "sac filler" theme. This includes lever-fillers, button-fillers, crescent-fillers, and others.
But sac fillers have drawbacks, as one might guess from their virtual absence in the modern fountain pen market. Sacs break down and require replacement. People tell me this is easy, but I've yet to try it myself. I'm not a very handy person and I prefer to send the pen to a repair person.
Furthermore, the ink capacity of a sac-filling pen is limited by the thickness of the sac wall itself. Maximum ink capacity requires a method that will fill the whole barrel with ink. Thus the one-time popularity of the Parker's "vacumatic" filler and the continuing enthusiasm for piston fillers.
Think of all this as a source of fun. I've yet to purchase a vintage pen that I couldn't fill and I doubt that you will either. At worst, you'll have to search YouTube.
I'll discuss filling mechanisms in more detail in later posts as they apply to specific models.