Actually, its perfect, and the only cookware I recommend for
I cook on a smoothtop range with nothing but antique Pyrex Flameware, and Corning Visions cookware. You absolutely don't need the wire spacer that was used for coil electric ranges. Both the pan and the cooktop are glass, so the heat transfer ratio is the same, eliminating the need for the wire spacer.
In fact, using the wire spacer could damage the stove, since without enough contact between the pan and the burner, the burner could overheat and crack the smoothtop.
I have tried almost every type of cookware on my stove, vintage Magnalite aluminum, enameled steel, stainless steel, cast iron, waterless stainless steel with copper and aluminum core, copper bottom Revere ware, and Modern Teflon cookware. Absolutely none of the others performed as well on a smoothtop as the Pyrex Flameware and Corning Visions.
Some of the other pans left ugly marks on the white cook top (the aluminum, cast iron, and copper), some of them danced and spun ( waterless stainless steel with aluminum and copper core, modern Teflon), and some of them just never seemed to get hot enough, as if they refused to accept heat from the smoothtop (enameled steel and stainless steel).
But the old Pyrex Flameware and Corning Visions are perfect. They leave no marks on the cookstop, they transfer heat at the same rate as the cooktop itself, they are easy to clean, well made, and I can see what's going on in the pans without ever lifting the lids. I never thought I would like using glass cookware, and when I tried it on coil top electric stoves, I hated it, but on a smoothtop, its the best choice.
There are tons of Pyrex Flameware, like your mom's percolator, and Corning Visions cookware on eBay, and at most flea markets and garage sales. I did not want to pay premium prices on eBay, and found mine for practically nothing at flea markets, until I had the complete set of each. If you are patient, you can get your cookware very very cheaply. If you are in a hurry, and have the cash, you can have it in a matter of days from eBay.
Look at your current cookware to decide for sure what you need. Pyrex Flameware is thinner, and doesn't retain heat as long, giving a cooking experience more like what you would get from you average set of aluminum, Teflon, or copper bottom stainless steel pans. It is also lighter, and easier to lift. However, because it is thinner and lighter, it is more fragile. You will want to handle them with care, and get rubber mats or liners for you sink, or they can be easily broken. The oldest pieces, (the ones from the 30's and early 40's with the removable metal wire handle), are a bit thicker, but still more fragile than Corning Visions. The newer, thinner pieces only come in clear, and the older, slightly thicker pieces came in clear with a faint blue or green tint. Also, Pyrex never made a large skillet or dutch oven, just 7 inch skillets, and saucepans in 3 sizes, as well as teapots, coffee pots, and double boilers.
Corning Visions is very thick, and retain heat for a long time, giving a cooking experience more like what you would expect from cast iron, enameled cast iron, or waterless stainless steel with the aluminum and copper core. They are heavy, and require more strength to lift, but are also practically indestructible. I have never broken a piece of Corning Visions, and I cannot say that for the Pyrex Flameware. Visions came in 2 colors, either cranberry, or amber. I prefer the amber. Also, Visions was a more complete line of cookware, with double boilers, dutch ovens, large and small skillets, and a variety of saucepan sizes, but no tea pot or coffee pots.
I have both types, the Corning Visions, and the Pyrex Flameware, since I like both, cook a lot, and find some tasks better suited for one, some better suited for the other. But that is my personal cooking style, your mileage may vary.