Maria Theresia Thaler Date Approximation Help.

I have done a lot of research on this coin and cannot seem to come up with an approximate date for this coin. When I put to what is on the web together with my coin I cannot (for the life of me) date it.. I don't know if there is too much miss information or not enough information out there to study. I have been told "The mint signature "SF" is intriquing as the coin type is modern(post 1817) but the letters in that signature look hand engraved (Pre 1817)." There is a blob of metal on the "A" in "CLEMENTIA." This blob completely covers the "A" and sits close to the "I." Any and all help is appreciated. If more pictures are needed, please let me know what needs to be seen and I will then post them. Thank you!