Not to throw cold water on the venture, but I know a guy that made very similar spoons with the same technique and sold quite a few of them and other tackle back in the 80's, it's a standard mold that is out there. He made and sold them for Stripers as well as Kokanee at the Gorge. I'm pretty sure no patent is on them so anyone could make them. This same guy has molds, production lead pots, mfg. equipment already and is set up as a mfg. business with a few workers. He is getting back into the Tackle manufacturing business with tubes, plastics, spoons, lead heads, anchors downrigger weights and more as well as other items.
I would not be surprised if he is working on similar spoons again, already...
As far as the comment of getting things into Sportsmans Warehouse, not saying it can't be done, but it is not like the old days.
If you don't have millions in liability insurance, EPA compliance, (Prop 65) especially when dealing with lead it's a tough go.
I would be cautious investing a lot into any "blue sky", and if buying the supplies and equipment as a hobby business to have some fun and make a little money have fun!!
Also, just curious how much did the spoons cost at retail if anyone knows? What would people be willing to pay for them?
Tight lines and good luck !