I have used both methods shown on Bruce Tharp's site. The internal mount, Option 2, is how the aileron servos are done on the 4*60. There are a couple of companies that sell plastic and carbon fiber mount plates for this method.

If it didn't come in the kit, I use Option 1 because it's easier and I have never had a problem with this method. Some times the servo on the left side will get oiled, but again, I have never had a servo problem with the oil.

As a matter of fact, I am amazed at how durable servos are. I squirt 409, Windex, whatever is handy all over these external mount servos to get the oil off and have never in many years of RC flying have I had a servo failure due to this.