Should I leave the back cover off for more circulation?

[Tubejunke]

I have a 1956 Philco 21" table model that I bought in 1982 from a local Goodwill store for use as my first bedroom TV as a teenager. Peeping in through the back cover and seeing what at the time looked like a small city of light led me to remove the back cover so I could see better and more easily clean inside and occasionally take some tubes to Radio Shack to use their tester. The set is now in the room next to me all of these years later and I wouldn't hesitate to watch it for the evening. It has never been restored nor shown a sign of needing it! I do wonder if the lack of a cover helped this set to be a MEGA performer. The circuitry outlived the CRT which I replaced a few years ago. The only bad part is I no longer have the back cover which got discarded by my dad when I went in the army. So far I have had no luck locating one and I would like the set to be complete. The Philco is about as plain Jane as they came, but it is my crown jewel. Having been with me through over half of my life and serving its purpose for almost 60 years, I can't ever see getting rid of it.