Can anyone identify this big 215 cab from 1972 or later?

[CLD]

http://stlouis.craigslist.org/msg/1228014442.html

Spotted this ad on CL yesterday and wonder if anyone can ID the cabinet.  Looking at my catalogs from '72, '74 and '75, the only 215 Sunn offered was the 24" wide side-ported 4 ohm cabinet.  Yet here is a 215 with the previous-generation center-ported style inside the bigger sealed box (26" wide and 18" deep) used for the 215SH and 415M.  I attached one photo below but there are three more on the CL listing.

I contacted the seller and he does not think it looks modified in any way, and still has the original Magna 1516s in it.  Does anyone remember this style of cabinet?

[loudthud]

It looks like a Sorado cab except the ports look a little too close together. The 215S from the 1972 catalog has offset speakers with a vertical port along one side. What makes you think it's from 1972?

[CLD]

That's why I'm so mystified by this one.  It's the same porting arrangement as my 1971 215 cabs (see photo), too, but mine are the traditional 24" wide, as was the later side-ported 215 cabs.  That's why I'm mystified by this one, which is in a bigger box.

The one advertised has the '72 and later dimensions (26" wide, 18" deep) just like my 215SH and 415M; it has the '72 and later handles (leather reinforced with a steel strip; note there are two on the side not one like in the old days); it has a sealed back like my 215SH and 415M; and it has Magna speakers.  Look at the pics on the listing. And in '72 Sunn started making the 24" 215 with those side ports, not the ones like we have.