That's interesting- the part number I used to fit to those boxes was a 2544 which is equivalent to Bosch/Century/Delco/Yuasa 55D23L. The 65D isn't listed by those manufacturers but appears to he the same as an N70 which would be too long.
Looks like the 65D is a little shorter than the N70 and a little longer than the 55D. Not available from any of the manufacturers that supply retailers here but a google search shows that Panasonic does one...
Maybe a market thing? I assume Australian z32s are identical to JDM z32s? the FSM i am looking at is bought in the US. My car is USDM car as well.
Battery trays and boxes I would assume are the same - they are between Australian Delivered and Japanese Delivered cars. A bit hard to comment - according to google that 65D26L battery is the same height and width (within 5mm) of the 2544 battery that I used, and 36mm longer. An N70 is 75mm longer and definitely didn't fit but the 65D26L may have been a better fit than the 2544, we just don't seem to have them in AUS. I haven't been in batteries for probably a decade now so my knowledge of the marketplace is also going to be a little out of date.