Australia 1966 Captain Cook 75c Stamp - 2 Varieties?

I don't have a specialist catalogue for the decimal era, so I'm a bit mystified by the unusual appearance of one of my 75c Captain Cook stamps. The one on the top in this composite image shows the normal version of the stamp. The one at the bottom, the one I'm intrigued by, obviously looks rather different. Does anyone know if its lighter appearance is due to some kind of printing error or whether there was a different printing that intentionally looked like this?



Thanks for looking!

ACSC
Q69
75c Olive green type E30
A re issue nov 1973 shade lighter.

come also variety non helecon paper
re cutting at base

An old ACSC catalogue can be had at most stamp club auctions
at $1-$3, they may even give them away.

Thanks for the info, Rod.

Hope life is good in WA. I'm thinking of moving to Albany. ...

You're welcome JJ
Wow! Really?
I'ts very nice down there, I am 2 hrs away
was recently down there for a half marathon.

Too busy for me, at 34,000 people
I like peace and quiet :)
The house prices should suit you :)

You'll have to go to hospital if you move to WA,
to get the constant grin removed from your dial.