Vintage Synth Repair

I've been readiung that running a 60hz device at a 50hz environment, 
can be destructive to the parts in the device - transformers can burn 
out or create fire, parts can get too hot etc.

I'm planning to get an old 1942 made Hammond G ("Government" - like CV) 
which is US made, 110v/60hz, and run it at 220v/50hz using a step down 
voltage transformer. To convert the motor frequency I'm going to either 
change the motor to a 50hz one or to place one of the converter boxes 
available for that application in Hammonds.

Should I care about the frequency issue ? can other parts get 
defected ? is that a dangerous step ? How many of you did that ?

Thanks.