The ones that MikeG and I got are the 12-14 foot size, part #12293. Backpacker3 also has one, I assume its the same size. My 2011 model doesn't have the front storage area; if yours does that may change the selection. ADCO says to measure your trailer--not including the tongue--and get the size that fits unless the size is close to the max for the cover you're considering, in which case order the next larger size. Check campingworld.com for measuring advice, plus they're currently having a sale on them.
It's never too late to have a happy childhood!
Lee, WU0V, and Courtenay, N0ZDT
2011 Rockwood A128
2000 Silverado 1500 pickup
60W solar system
2000W inverter generator