I am using a chinese drum switch on my milling machine... it's not good...
The switches that I am buying for my mill are not adequate to carry the current required by the motor. I am getting about 6 months of use per switch...
The problem is that the contacts inside the switch are tiny... everytime I turn the motor on or off, the contacts will arc for just an instant... over time, this arcing burns the contacts and ruins the switch...
I'm not sure what drum switch you are looking at... it may be built better.
FWIW, I bought a reversing drum switch off ebay for my drill press... it is a Dayton, and was a new switch. I paid $33 plus shipping.
I'm in the process of 're-designing' the electrical system on my mill... hopefully eliminating this problem.
-Bear