All my tubes went in the trash with my sewups.

Folks, please let me use this thread to possibly put this subject to rest. Datsun called it a Cushion Battery and the part # was 24480-E4600. It has been No Longer Available for more than 25 years. It is my opinion that Nissan decided to use such a thing as they simply didn't like the idea of 2 metal surfaces making contact.  A little like the 240 rear bumper end brackets. When Nissan started the Z Store program they commissioned Banzai Motorworks to reproduce it and a whole slew of NLA parts for use in the program. They stole/hired a quality control engineer from Boeing to make sure that what they bought from Banzai was correct in every way. Wonder what became of her? Although the picture is a bit unclear - I hate to take such a rare part out of the original bag -  a New Old Stock cushion is on the left and the reproduction on the right. Be careful - there are those who have probably never seen the real deal selling what they claim is an accurate reproduction - beware. The cushion and battery frame were held to the firewall by the fasteners shown in the second picture. They are a 6mm x 23mm long Phillips hex bolt with a captive lock washer in clear zinc. The flat washer is  6mm with an OD of 18mm in yellow zinc.     Cheers