You can check out enforcer-bait-molds e-bay where I have picked up quite a few.
Zeiners(zlures),enforcer-bait-molds - injector
LinMar (linmar713), open pour and you will find periodically used silicone open pour.
Bearbaits, M-F Manufacturing,and Mudhole - off webs.
Also google up soft plastic molds and you will find a substantial number of suppliers.
As far as soft plastic by the quart/gallon I have purchased from LimMar Fishing and it is reasonably priced.
Good luck and hope to see your results
GOD bless our troops
SS581 - Last Diesel Sub