Dan, from my experience, the model year changes over in late summer as to what you can buy. There often is leaked info beforehand however. Althought, the newer model may have distinct changes from the previous year, FR will often be making changes throughout the year in what comes off production. Therefore there may be differences between say two 2014 MHs and only the VIN six digit serial number will give you what you have.
Gale & Hank- 2012 Berkshire 390BH