Romano - I would say it is fixable - so don't think about getting rid of it.

Probably by tonight a couple of the other members will have logged on and I'm sure some of them have worked on Hankins before.  We'll have a fix. 

Can you check in the manual and see what fuse F3 on powerboard is for?  This will help us track it down.. 

One of my old pins had a similar issue of fuse blowing on startup.  Swapped a transistor on the driver board (10 min fix with soldering iron) and for under $10.00 it was up and going.

If you can lift/tilt the playfield up (remove balls first!) have a look at the pop bumper which is not activating and you will see a couple of leaf switches .  Note how they are - without bumper down and observe the gap (if open) or switch closed.  Then check same on the two which are locking down and compare.  Also make sure no wires have come of any of the coils driving the bumpers too.

Do you have a digital multimeter handy too.  You may need it when the others get on to help with some diagnostics.

If you are able to maybe start another thread in the My Gamesroom area I would absolutely LOVE to see some pics of your pin.  I literally spent weeks playing it at a caravan park when I was a kid and loved it.  Some of my happiest pinball memories!!