Far out, I even commented on that post on RR back in '08 and I don't recall it at all. The joys of motorcycle accidents, I guess.
The Deluxe & Standard versions of the LSI are different to the Export version. As far as I'm aware, the deluxe didn't necessarily mean the larger engine, they were optioned with either.
The only differences that I am aware of between the ALSI-E and ALSI-E (L) is that the L stands fro L.H.D (Left hand Drive). In fact it references in my 1962 Prince Manual that "Left hand drive model is mentioned in this manual but it can be easily referred for right hand drive model." Which translates to them being the same but for the location of the steering wheel and associated shifts of equipment.
IIRC the easiest way to spot an LSI-E is the side trim is much larger with a downwards point on the lower section as can be clearly seen on your car. The domestic Deluxe version has a slimmer arrow shaped trim section and the Standard (if memory serves) has a chrome strip.
I believe all that information is in the Parts Manual I have which is inside my S21D-4 where it is being stored so I don't have easy access to it at the moment.
I've deduced or rather guessed from the documentation I have viewed in person, that the A in A
LSI is for the GA-30 and GA-4 and the B
LSI is for the GB-40 and GB-4 powered versions. The A being 1500cc the B being 1900cc.
This does conflict with some information though, so despite making sense there may have been instances (particularly the Export market) where there's an exception to that rule. I believe the pink one is still stamped ALSI on the data tag and yet is a 1900. Somewhat contradictory but the fact it makes sense for the rest of the documentation and then further instances of the Prince and Nissan model designation system makes me wonder.
The article is somewhat strange (although understandably high in praise) I'd be interested to see why they think the 1500 was called the 1700. perhaps a typo here and there in their documentation given, it would certainly not be the first time.