I am DAFF accredited Tim - and I will say this - the best thing the vets conducting pre export examinations and vaccinations on behalf of the Australian Government can do - is use the little stickers that come on almost every bottle of vaccination and place them on the vaccine certificates.  That combined with writing your name and address on the certificate clearly is really helpful.   Those stickers have the Manufacturer, brand, expiry date and batch number written on them....stick them on the certificate after printing.   With regard to the due-date - I haven't looked at it yet but you should be able to retrieve that info in a document quiet easily...HOWEVER - and here is the catch the reminder is not updated until the visit is finalized...hence...it wont be retrievable until AFTER they pay....which is highly frustrating...because documents attached to products are generated at billing. The final alternative is to use a jxpath to call the reminder template linked to the product and call the due date that way....havent looked at it...To be honest the certificates need to be signed in blue pen anyway and I just right in the due date then...Rabies vaccinations are also interesting because the Australian government also requires an EFFECTIVE date - the date when the vaccines starts being effective (for Rabies this is arbitrarily 3 weeks after injection) 

You can download the Australian governments official rabies vaccination certificate (International Rabies Vaccination Movement Certificate from the DAFF website as well) or atleast a template - if you cant find I can send you my ODT formatted one...

BTW we don't really care about anything other than the last vaccination. History is sort of irrelevant.