I like your venture, and endorse what you’re doing; however, if you’ve spent...
then you missed Honig’s. In its role as “official” (unadvertised) MLBU outfitter, Honig’s supplied and stitched on all the numbers for MLB Umpires, on all shirts, jackets, and plate coats. You can’t get any more authentic.
I’m welcome to see what you’ve got. I will encourage you to resist the whining, griping requests you probably get ever so often for 4” red numbers – let that arcane practice die in HS navy shirts.