Excellent thread. Really appreciate the information. Followed up that suggestion by Pam and rang Allmaz in Clayton. Advised me to go direct to Centre Road Batteries in Springvale (they were so quick I didn't get to tell them Pam sent me - sorry). He said he had a 2 year warranty sealed non-AGM with breather tubes outlets for $115 and he throws in a free long clamp arm in case it's needed (turns out that must be for an NA and don't need it in an NB). When I picked up the battery saw it was a SuperCharge calcium Silver SMF43 (assume it's the same dimensions as the Gold MF43 - didn't ask if he could have put the breather tubes in a Gold as it was too late) and he adds the 2 breather tube outlets himself along with 2 lengths of tubing if you need them. I was very happy with the service. So have now got a fairly cheap sealed battery with breather tubes. Have paid a premium for the breather tubes but am happy with that. If it doesn't work out I'll next try the AGM FullRiver HC20.
As for installing in the NB, it was just a little too wide for the plastic base, and I split that trying to make it fit
and for now have nothing under the battery but metal. With the bracket across the top of the battery was just able to squeeze that on and it's all secure and clamped down. The existing cars breather tubes slid on the outlets, although turned one outlet around so they both faced the same way and re applied the silicone. Have included a few pics in case that helps anyone else.
Battery showing added breather tubes.
MX5-battery-new-01.jpg
SuperCharge Silver battery & split plastic based
MX5-battery-new-02.jpg
Installed
MX5-battery-new-05.jpg
Complimentary clamp arm
MX5-battery-new-06.jpg
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