Ah...Yes...sharpening!
So often good tools are found...yet...many think not of the moment when the tool is no longer "sharp." I have often wondered if this is why it seems more "edged tools" are made than we actually need? Folks may use them...few think of what it takes to sharpen them...and just buy another.
Your tool William is most likely sharpenable. Some have very good hard steel laminationed with soft...some are just soft iron perhaps with only a marginal temper....Either way, you can keep them sharp with the correct "sharpening" and/or "honing," tools.
Above are just two examples of 100 (1000?) of designs. If you can get me a picture of the edge profile...I can, perhaps, give you a good outline of method to re-sharpen. Also, how long did it take in "working hours" to become dull? Please not...good sharpening "feather files," and the other file types, plus multiple
water stones may cost more than the tool itself...yet...are a necessity to keeping tools in good working order.
Regards,
j