Arisaka Type 38 6.5 Safety Knob Early Large Tang Part# 499730

I purchased a used Arisaka Type 38 6.5 safety knob, Part# 499730. The one I received says it’s for the T38 6.5, but also says “-SAMPLE-, SAFETY KNOB, EARLY LARGE TANG.” I tried to assemble it, but the safety knob lug is tiny and closer to the end of safety knob pin. It will not go far enough into my T38 6.5 firing pin to be able to rotate and assemble this safety knob. It is also only marked with ### on the safety knob pin, the knob doesn’t have the distinct diamond pattern, and the tang comes more to a point than rounded. Any help is greatly appreciated!