The bottom 2 tools look like the ones made for a jeweler to hold diamond cut jewels. Note the 3 prongs with cuts near the top to grip the stone and the slide used to hold it tight. The top one with just two prongs may have served the same purpose but not as effectively as the others.
Thanks are due to 'dross' for his kind help in identification of the discussed tools. In another comment on the topic, offered outside the MB, my assumption that these tools might be 'home made' was questioned. It appears that they might be professionally made in the latter part of the 19th century. Comments regarding this possibility are welcome.