The only sfw to pdf conversion we know about, would be export of old Lotus WordPro drawings (.sdw) to PDF format, which might not be easy today, but still doable.
Your best option is to download Lotus WordPro installer from one of the abandonware websites (WinWorld library for example) and simply use the print function to get the drawing in PDF format. A viable alternative would be to find and use graphics tool that supports SDW format, unfortunately, we do not know about any.
Updated: September 11, 2023