Hi! It's possible that the screws and washers you need aren't standard sizes. They may need to be purchased from a music equipment or instrument repair shop. It would be best to check the manufacturer's website. Look for any relative info on the size of the screws and washers you need. Besides, you could check if replacements parts are sold at stores such as https://www.scrooz.com.au/. It's essential for you to use the correct screws and washers to ensure the toaster is secure and stable. I hope my advice will be helpful.