These blue WWII OPA tokens are actually pretty common -- worth a few cents apiece.
$1 to $3 depending upon the condition of the token.
Found one on EBay for .99cents plus $2 Shipping.
Office Price Administration:HC 40cHT 40cMM $5.00MV $235.00TH 40cTY 40cUC 40cUH 40cUT 40cUV 40cUX 40cUY 40cVC 40cVH 40cVT 40cVU 40cVX 40cVY 40cXC $2.00XH 40cXT 40cXU 40cXV 40cXY 40cYC $2.00YH 40cYT 40cYU 40cYV 40cYX 40c
Red OPA Price List:HC 40cHT 40cMM $5.00MV $235.00(X-Unknown?)TH 40cTY 40cUC 40cUH 40cUT 40cUV 40cUX 40cUY 40cVC 40cVH 40cVT 40cVU 40cVX 40cVY 40cXC $2.00XH 40cXT 40cXU 40cXV 40cXY 40cYC $2.00YH 40cYT 40cYU 40cYV 40cYX 40c
2500
Opa Opa was created on 1999-07-05.
No, opa-opa is a self-aware spaceship with no gender.
There were used in the food rationing during World war 2.
Red Token And Value:HC 40cHT 40cMM $5.00MV $235.00TH 40cTY 40cUC 40cUH 40cUT 40cUV 40cUX 40cUY 40cVC 40cVH 40cVT 40cVU 40cVX 40cVY 40cXC $2.00XH 40cXT 40cXU 40cXV 40cXY 40cYC $2.00YH 40cYT 40cYU 40cYV 40cYX 40c
You could say either 'grootvader' or 'opa', but 'opa' is far more common in the Netherlands.
Toyota Opa was created in 2000.