I know this may sound like an odd question, but I currently have no sure way to identify the year my burb was built. There is no build plate as it appears to have been removed - most likely when it was imported into Australia. At the time there would have been age restrictions on importing vehicles and it has been registered as an 81. However the previous owner(who had it for 17 years) said its an 88 and I found a 89 service manual in the love box. Any ideas of a sure way to identify year of production?