the cover over the coin tyray is due to the fact that this is / was a casino machine, and paid out in the base it sat on.
there is more than likely a large hole in the bottom of your machine.
the criss cross name bar means is pays out on certain combinations similar to the jennings tic tac toe features... three bars in a diagonal pattern pays as well as in a straight line.
the bell serves 2 functions. 1) to call the jackpot girl. jackpots were hand paid as nevada law (nevada gaming commission) state that (this may not be verbatim, but... ) jackpot amounts to be paid must be known / shown in advance, not random. subsequently, a mechanical fill jackpot such as the older mechanical machines had, could not give a guaranteed amount ( unless it was a handload jackpot machine).
2) the second function the bell serves is when other players hear the bell, they get excited and think... ("OH, BOY! THEY JUST GOT A JACKPOT... I'M NEXT!"...) , and they start pouring coins in as they can to chase that dream.
he tin shield over the reels is to prevent some crafty cheat from sneaking in through the back with a wire to try and stop the reels in a winning position.
this machine is listed on ebay:
http://www.ebay.com/itm/ORIGINAL-1940s- ... 5d508f2ca2