Hello,
I'm not sure if we carry a suitable replacement for your thumbturn but we've related the three replacements that we carry on this page for you to review. In cases like yours, I would generally recommend starting by comparing the specifications of the 40-049 lockset to yours. This isn't exactly the same as your original, at least not in terms of style, but the design is very similar. I think it may work as long as the dimensions match up to yours. If so, replacing the entire assembly can be a safer bet since you know that all of the hardware will be compatible with each other. Take a look and see what you think.
