If I had an Odyssey battery I would invest in one of these
http://www.odysseybattery.com/documents/ody_chargers_sheet.pdfThese cells use totally different technology and temperature during their life cycle plays a crucial part in the cells functionality. As a rule of thumb for every 10C above 20C that you expose it to you half the useful life, as will be clear an engine bay is far from an ideal environment. (don't know where Aero's are sited but a lot of Classics are under the bonnet)
The CTEK could well prove to be too crude an instrument for this mat technology cell and be causing damage due to either too high a charge rate or overcharging leading to overheating and damage to the cells.
Looking at the spec on the Odyssey charger it is an intelligent one, certainly worth one of you getting one and trialling it in an attempt to provide a longer term solution.
