DanM

For jump rings,just wood dowels. For other shapes maybe one like this ... https://www.catfish1.com/threads/diy-wire-bending-tool.247085/ Do you have photos of what you want to make?

Maybe fabricate it from sheet metal.

If you have live roses,you might try this process. https://www.ganoksin.com/article/casting-orchid-flower/

Maybe you could get the same type of texture with a course wood rasp.

Flush or raised inlay?

People have been using it for jewelry for at least 30+years. https://www.google.com/search?q=fordite+jewelry&client=firefox-b-1-d&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjtvJiUqaX0AhVHlWoFHa9ZB8cQ_AUoAnoECAEQBA&biw=1250&bih=617&dpr=1.3

Jeweler's hand vise..... https://www.penntoolco.com/grobet-usa-hand-vises/

Have you tried boric acid as a substitute? https://orchid.ganoksin.com/t/adding-boric-acid-to-molten-metal/17426

Looks like a standard rolling mill used for jewelry manufacture and other non ferrous uses.

What are the objects you are trying to cast?The sprue is very wrong and it does need "vents". The base for the pour appears flat and should have a large "funnel" shape.....see example.

Did you prep the crucibles?

I glued the pattern onto brass sheet and pierced the piece with a jeweler's saw. A little file work to even things up and then was clamped into my mini unimat. The knife side was milled for the buffalo horn insert.

At one time I made a number of brass handled cartouche knives.Photo of a dug original and my reproduction.

There is a bit of information about Kris blades on this antiques forum, https://www.google.com/search?q=site:antiquers.com+kris&source=lmns&bih=617&biw=1238&client=firefox-b-1-d&hl=en&sa=X&ved=2ahUKEwjTvPb1we3yAhUITVMKHUe_AI0Q_AUoAHoECAEQAA

Did you look at the link I posted in Joshua's tutorial? The book will tell you nearly everything about mokume.