Any ideas on how to remove an International furnace from a 1965
Safari. I dont think it's original but possibly replaced early on - as there seems to be a larger whole cut through the skin - possibly because it was too big to get in. I have removed the electrics, gasline, exterior vent and all the internal rivets I can see/access and would love to be able to remove it from inside so I dont have to remove any exterior rivets. The furnace moves an inch or two but it wont come out.
Do you think I will have to remove this exterior panel?