Whitfield Advantage Plus question

[CarbRage]

Hello all, been creeping the forum for a while and finally decided to post a few questions about my stove. I was luck enough to save my first advantage plus from the scrap yard along with a crap load of duravent. The second one was given to me by an uncle who purchased a new stove.
1) What is the max distance for the chimney pipe? My house had an existing wood burner and i ran 13ft of 3" duravent to the existing 6" thimble. it has 2 45's and one tee with a clean-out. See pic 1
2) My first advantage plus did not have removable plates on either side of the burn pot. Only what appears to be a metal knockout. Has anyone attempted to remove them for clean-outs? see pic 2
3) I did replace the glass gasket on one of the doors and only 3 sides had material. The top had a 2 piece bracket and no material. Airwash? Also need to replace the door gasket and I used 1/2" but that appears to be to small. see pic 3
4) Where would one buy turbine oil locally for the motors or an off the shelf acceptable lubricant?
Do you recommend upgrading or replacing any parts? ( all i see in my future is some blower gaskets)

Oddly enough both of these stoves are the same model but one has clean-outs on the sides under the fire brick the other has the knockouts pictured above.

One stove has a larger hot air exchanger port above the door the other has a more narrow one.

Thanks for any help.
Rich