Sorry, haven't visited the site for... well about 10 months!
In short, yes, I succeeded. My 110 is in storage right now but I can remember the basics. Internally the preamp and power amp are two very separate units. Its fairly easy to trace the power amp input, disconnect it and connect a 1/4 input jack.
Note that the power amp is 'dumb', it is just on or off, no master volume etc. So whatever preamp you use will need enough output to drive the power amp to get volume. I used an old line 6 xt pod live which has a preamp mode and also a DHA valve preamp which could do the same. Any pedal will probably do it, but you might not get the full output.
Mine might be out of storage in a month or so, i can take a pic of the internals then if you need it.