Yes, it is actually made in the 1940's. My grandmother played it for years in a hawaian band(well, hawaian... not actually in hawai, hehe).
Yes, it does have a pickup, but again, a pickup from the 1940's. To play with it you have to plug one of these in the back:
The output cables just go into your stereo. They don't fit on my regular amp...
Gauge strings? I'm pretty sure it's this: 0.14 0.14 0.18 0.28w 0.38w 0.50w. Not completely sure though.
It's tuned to open E. I prefer that to open G because I think open G has a happier(that's a funny choice of words) sound than open E. Open E seems more bluesy.
Do I use it? Rarely. I play regular guitar normally, sometimes with slide, especially because it's pretty hard to hook this thing up. But the tone is really cool.
I've also got an instruction manual from that time. It's really cool. It's in dutch, but not regular dutch. Old dutch. Dutch people will understand... it says:
DE HAWAIIAN GUITAAR
en beschrijving der onderdelen