Sorry to hear this, but Brother machines of this time period are NOTORIOUS for broken camstacks. You'd have to buy a donor machine with an intact camstack and that may be a hard task. Getting the camstack out and putting it in your machine won't be an inexpensive job and it's possible the delicate nylon piece may crack while doing the job or soon after putting it in the machine due to its age. Glue doesn't work and fillers are just a stop gap as the crack will widen over time. You can try it as you have nothing to lose, but the stitch outs will be effected either way because of this gap in the camstack. Try it as a straight stitch machine. It's possible you can still use it that way and just not use the specialty stitches.