I worked for years in consumer electronics repair. Imagine CRT TV's with tar so caked on the screen that there's no blue left, just a yellow/brown stain. After cleaning the screen, the lady says "That's amazing; I thought the tube was shot for sure".
Try Lysol Basin Tub & Tile cleaner (white foamy spray), applied CAREFULLY onto a cotton swab and carefully applied to the surfaces of the camera. Leather and simulated leather can soak lots of the tars and gasses into the material, so let it sit awhile to soak before drying. When removing the residue, use a gentle motion with a soft cotton cloth. You should see a yellow/brown stain on the cloth to indicate you're removing debris.
After you're satisfied that you've cleaned off the film of gasses and tars the best you can, you still may want to place it in a zip-lok bag of dessicant for a while, to try and remove more residual odor that may have seeped into the camera's seals.
Good luck.
~Joe