Thanks everyone for the replies. The phone has a single 4 wire ringer. I have tried wiring the ringer as described with and without the grey/slate grey and still nothing. The ringer coil looks as good as new, not that means it will work. Is there any easy way to bench test it without sophisticated equipment?
The ringer is marked 65a if that helps at all? It is identical to this one on ebay: (https://www.ebay.com/itm/261352379741?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649) which I will gladly buy if that will fix it? Thanks again for the help!