There is a machine on Topeka Craigslist right now that has Mason Irons and a Mason Rotary mchine in it. Funny, it has a wooden insert for the White T-shirt. Looks just like my older White rotaries, except for the t-shirt and decals.
Hmm T-shirt is a bobbin cover that has a similar shape to a T-shirt. I guess I don't have a pic handy.