I know some like this model a lot. I don't know how much time and money you are willing to spend to get the machine nice again, but it's usually not to much. I looked up Helen Howes site and found
this. She is worth contacting and has parts not listed on the website.
Another place for help and good advice is the relatively new
groups.io and since yours is made after Singer bought the factory, you could post in the
Singer group too.
Best of luck with your project. If you are new to cast iron straight stitchers you are in for a pleasant surprice. It can be some work to get them running and stitching again.
If you still have the picture, it can be easier to link to a /open album. It is usually about shrinking the picture to the right size, but if you can embed the picture from another site it's not as fuzzy.