A lot of antique radio restorers prefer to cut open the can near the base, remove the innards, and replace it with a modern (much smaller) capacitor. Gluing it back together and polishing it up can make it look pretty close to original.
Here's a pretty good write-up: http://www.faultlineaudio.net/the-work-bench/2013/1/15/restuffing-a-multi-section-can-capacitor.html Kyle
