Not all vintage irons recommeded nor called for distilled water, it varied by manufacturer and even between models.
If you want a vintage steam iron, I'd stay with models from about the 1960's through 1970's such as those sold by Sunbeam,General Electric, Kenmore, Wards and so on. Many of these later models unlike their eariler cousins can produce steam on more than one setting, usually from wool to linen. Some even produced steam from all settings including man made fibers. Others however will only produce steam at cottons or linen. This means if you wish to iron a cotton/spandex shirt with steam, you are out of luck as the high cotton setting while providing steam is too hot for spandex and will destroy the shirt, and the man made fiber settings while cool enough to work on spandex, won't produce steam. Same goes for ironing silk, rayon or in some cases pressing wool.
Many of the irons from the above mentioned era have features still popular today, such as: spray functions, visable water sighting glass, teflon coated iron shoe surface, burst/shot of steam and in some cases self cleaning.
Older irons from say the 1950's and before tended to be used more for dry ironing (as most housewives ironed damp cotton and linen, fabrics dry)thus get very hot and in some case are very heavy, but do not produce the amount of steam one would find from later irons. These irons also are more likely only to produce steam when set to their highest settings.
If you can,check local thrifts and estate sales for NIB/MIB irons so you can see the condition before paying. If buying off Fleabay, examine all pictures well and again try to buy new in box and never used. You don't want some steam iron that has been used by who knows whom, with god only knows what sort of water. It is likely the thing will be clogged with minerals and will spit brown water on your ironing no matter how much you clean the water tank.
Hoover, Proctor, Proctor-Silex, Sunbeam, General Electric and Kenmore brands are generally all good. Sunbeam and GE had some great irons from the 1950's to 1970's that not only steamed well on many settings, but came in cool colours like Cha-Cha Pink.
On more thing, the first few times you use a vintage iron, try it out on something you don't care about or old sheets. Irons from the era of "damp ironing laundry dry" usually are VERY hot (they had to be to speed up all that damp/wet ironing), and a cotton setting then, is much hotter than a cotton setting today. You can easily scorch whatever you're ironing if you are not careful.
L.