It may well be an Answer one, but it's not the same as the one on eBay. That hasn't got the extension bits and the holes look round.
None the less, I would buy one of those as it's pretty close.
That alloy tank was pretty agricultural, actually. But I had ordered a plastic one from the U.S., it got here a week before I was leaving for Finke only to find it was for an '85 model. So I had to get a local engineering joint to whip that up for me. Cost me $800.
As for "progressing"............ I wouldn't say that!
I'm still buying up bits for it, but I haven't actually done any work to it.
Starting to get a little more interested at least and hopefully next month I'll find some time to do a bit on it.