Is this (original?) installation of a Majestic L36A fireplace correct?

[oldplace]

I bought a house (c. 1970) from the original owner. It has a Majestic L36A fireplace (pics attached) w/ fireplace doors that are old-looking, worn, brass-plated, rusted with non-functioning screen mesh. I removed the doors and began inquiring about replacements, learning about the importance of proper door type for ZC fireplaces, and how there should be high and low vents on the door assembly to allow for room air to enter the outer chamber of the fireplace box, to cool the box and ultimately escape from the top of the chimney. The problem is that the fireplace opening is framed on all sides with ~3/8" thick slate pieces and they cover the area where there might be (??) firebox vent openings. In looking at the L36A manual found online, I can't tell if there are vents in the front of the firebox. When I look at replacement doors indicated to be for the L36A, the web sites all show the size opening as 24x36 but, with the slate pieces, the opening is actually 23x33. Is anyone familiar enough with the Majestic L36A to know 1) if there are vent openings to the firebox in the front-top and front-bottom; 2) if the installation I have is correct/not correct; and 3) some suggested door replacements (make, model, vendor)? Any other information would be greatly appreciated. Thank you.

 

[bholler]

I looked through the manual (which is not great) and dont see anything about vents. So i would guess this is an insulted box not air cooled but i cant be sure hopefully some one who knows the unit will come along to help you. But i will say at that age before spending any money on it i would recomend a full inspection of the unit and chimney. It is well past its expected life span and there may be issues with the condition of the box and or chimney.