Lopi Answer question?

I recently acquired a used Lopi Answer stove. I know it is a little older as it doesn't have 3 combustor tubes, this one has one round front tube and rear air holes in the square tube. It also doesn't have the side convection vents. Does anyone know when Lopi changed the design to the 3 tube style? Also if anyone has had any experience with this stove I would like to hear about it. Also if anyone knows what size the door gasket is that would be helpful also. Thanks

I bought a used Answer myself early in the season to heat my basement. Havent' actually fired it up much, as I'm not often using the basement. Anyway, I emailed Travis Industries through their website with my serial number and within a couple days I had the stove dated as being built in 2002.

MarkG