I was figuring what I would charge for 100 solid paradox type slugs and came up with $ 150-$200: $45 for the lead and tin and the rest for time and shipping. The old style moulds cast .736 to .740 so you would need a sizer of the correct diameter. Most common size dies for the old paradox rounds were about .735ish. I have moulds I might be convinced to loan (I have before), but no .730 sizing die. John Millar might loan you a mould and may have a sizer or could easily make one.

It seems you have a modern rifled bore? You are better off slugging your barrel, checking twist and ordering a fresh mold from accurate. I've looked at their designs, they look good, but I have no personal experience with them. If it did not work, it seems you could readily sell your new mold and recoup much of the expense.

Good luck, I hope you post your results.