Hi Angelo,
The email has stopped working tonight but I did receive your message from last night. Good work on finding the problem!
I have not worked on a Bally with the boards under the playfield but they generally only used two sizes of connectors. The Solenoid board has both sizes, .100" for the small connectors and .156" for the large ones to give you a comparison.

I normally order the connector pins through www.farnell.com.au as they are local to me but www.pinball.com also stock these. These connectors are the crimp type so you would need to cut the old connector off and replace it. I haven't had to replace the housings yet but www.pinball.com also stock these. Ed at Great Plains is very helpful and will be able to suggest the correct ones if you can't source them locally.

regards Derek

Manufacturer: MOLEX
Order Code: 1653857
Manufacturer Part No: 08-52-0113.

Manufacturer: MOLEX
Order Code: 1462631
Manufacturer Part No: 08-52-0123