I have one old machine without a threader as well - My trifocals give me fits when I use it. I have solved the problem by using old fashion Beeswax in a holder (the kind that you Grandmother used to use!!). I run the thread end through it and then in the waxed portion cut at a small angle - the thread usually goes though the hole in the needle nicely. I also use this when threading the loopers in my serger as well as hand sewing needles.