if you are patient you can get antimony ore to alloy in.
the way i do it is to add tin first, then hold that at about 600* then use a light sprinkling of marvelux. light, lighter, salt shaker light.
then crush the ore to about 1/8th inch sized pieces, set on top and stir.
you may need to add a shake more of the marvelux as you go but don't get carried away or it will cover the ore and it won't alloy in.
patience is key,and keep a slow stir going.
once you have it all worked in, turn the heat up to about 800* and use a good carbon type of flux.
now if you have antimonial bars then adding it in and using a carbon flux plus raising the temp and stirring well and fluxing again should get it all in.
see a pattern there?
pewter is a good source of tin when you can find it, just be aware that some brands of "pewter" is not really pewter. iirc wilton is another type of metal kirksite or sumthin.