This is the first Lancaster petzval that I've seen. It is engraved 'J Lancaster & Sons Birmingham'. I've used a Lancaster wide angle rectigraph for years and it is one of my favorite lenses.
The focal length from the stops is about 9", so has an approx 9" image circle. It should cover up to whole plate for landscape, etc and 8x10 at portrait distances. Corners will be soft or dark on 8x10 at infinity (on my gg it looks like it lights up the whole thing, but less so at the corners). Focus knob mechanism is present and working but doesn't travel very far. Weight is 45oz, approx 5 1/4" tall; flange is included, one waterhouse stop is included, approx f3.5 wide open; flange is approx 4 1/2" in diameter so should barely fit on a 6" 2D or Deardorff type board. Note: the lens cap, ruler, penguin, etc are not included...
Each rear lens glass is rolled into its own metal capsule and these screw together to keep the lenses properly spaced at all times without the use of the metal spacer ring seen in cheaper magic lantern lenses. This is the same sign of quality you'll find on a Ross or Dallmeyer petzval. There is a miniscule nick on one of the rear elements. The front element has an odd artifact which you can see in the next photo. It doesn't seem to affect anything. But it does look like one of Jim Galli's little green men might be waving to you when the lens is held at an angle...
Price: $345 + $14 insured priority shipping in the USA. Paypal or USPS money orders are both fine. PM or EMAIL only, please. $$ to APUG if sold here.