Where do these bits come from

[ManicMan]

^_^ makes sense. I keep forgetting them Blister machines

 

[orkwrangler]

the Whirlwind or Razor back as a metal add-on pack without the plastic rhino parts at one point

These are 40K 2nd edition tank kits - the Rogue Trader Whirlwind was a White Dwarf conversion guide IIRC. The 2nd ed era was pretty good at giving you a box with something you could assemble & field immediately, something sometimes lacking before.

No doubt mail order would sell the bits separately, so possibly separate in catalogue pages.

 

[ManicMan]

yep, I know about the guide.