How old are these pin spike tires?

[RCcoachworks]

I am trying to figure out when some tires I have were produced based on their packaging. I'm not sure when these are from, but the Y6001 part number makes me think they're vintage, as well as the yellowed/dusty bag. Any thoughts? I'm just trying to determine if these are truly from the early days or not.

 

[frameskip]

My understanding is that the “Y” and “X” part numbers are the MRC part numbers for when they were the US Tamiya distributor. These look like original spare parts to me.

[RCcoachworks]

Thanks for the info. That makes sense - all the MRC Tamiya part bags I have also have the same type of part number, X#### and Y####.