Tuck Pointing Trowels

I have butter mortar joints on my home and I need to make some
repairs. To do this, I need extremely narrow tuck pointing tools. All
I can find on the market are 1/4 inch trowels by Marshalltown. Way too
wide. I need 1/16th and 1/8th trowels. Does some hardware store or
masonry supply house or restoration group have such tuck pointers?