http://www.cameramanuals.org/pdf_files/bilora_bella.pdf

Here is the manual , I found a 66 and 3C models at the google , same or not , I dont know the brand name of the shutter also. Tell us what is written for the producer of the shutter ? And if there is a shutter serial number , give it to us also , Someone with a 50s catalogs could help.

Here are the wonderful sites , bottom ones are for idea also.

http://www.daniel.mitchell.name/cameras/index.php
http://rick_oleson.tripod.com/index-55.html
http://www.kyphoto.com/classics/foru...tml?1194277522
http://www.kyphoto.com/classics/foru...tml?1334015922

Welcome to APUG and good luck , send some photos during repair and someone would like to help you.

Umut