Mine was a double pump like yours, part number AUF406, equivalent to the AZX1404, which is in turn identical apart from the fittings it is supplied with to the
AZX1405, sold by Burlen. I would presume that the
AZX1405EN is simply an electronic version of the same pump. I'm no expert, but I suspect an electronic pump would give similar advantages and drawbacks to electronic over points ignition
This is what I put on the BOC Wiki about it at the time (July 2007):
"The fuel pump on my 410 recently gave up the ghost, and so I was obliged to investigate current replacement options. Burlen Fuel Systems were very helpful; my car had an SU twin pump, model AUF406, fitted as described above, in the boot. The AUF406 is now known as an AZX1404. The AZX1405 is apparently the same but comes with different fittings for the fuel lines, although if you are replacing a pump you would already have the correct fittings so it should be trivial to swap them over. Burlens offer a restoration service, but that (at time of writing) has an 8-week turn around, and costs only a few pounds less than buying a new pump. However, they also sell overhaul kits, which contain new diaphragms, gaskets, points, and all the consumables apart from the main coil. These were fairly straighforward to fit, and have the part number EPK300. You need two kits for the twin pump obviously. Mine initially still didn't work, but once I'd taken it apart, checked all the setup, and put it back together a second time it seemed fine. If the coil itself has failed (which according to Burlens is extremely unusual) the unit will need complete restoration or replacement and the overhaul kits will be of no use."