I've been shooting a similar lens (I'm guessing the focal length is somewhere in the 12"-14" range), a Seneca Portrait 6 1/2 x 8 1/2, F5, which sure seems like the Wolly Vesta. BTW - if yours is truly a Vesta copy, it is also a convertible - use the rear element alone and I think you'll be somewhere around an 18" f11.