My 60's Williams Oh Boy had the same transformer listed (15A-6771) - It had a stepdown fitted.
These Auto Transformers were fitted to some European imports (refer pict) - But would not recommend them.
This is the stepdown I fitted to my SweetHearts
Bought here:
http://www.ebay.com.au/itm/140709227591?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649Would definately get the one Retropin recommends - Will buy this one next time I need one
Cant work out why they fitted transformers on the front end of playboard - Down right dangerous.
