I've done a few things with the Whoopee now:
More purchases
First, after transporting it from the warehouse to my home a couple weeks after the purchase, I bought the machine's flyer on eBay, as well as complete sets of rubbers, light bulbs (#47, I don't want the plastics to suffer anymore), a used shooter rod, 5 bumper scoring NC switches (many thanks to the guys at PinballHQ for helping me identifying them; they were all broken, and I wanted to have spare), standard 1 1/16" balls, and backglass connectors (which were broken too, as you can see on the pictures).