RE shields on mufflers

[big r]

I was just looking at a picture of an 85 and the mufflers look just the same as the ones on my 86. Also in the clymer manual the grab rails are one piece and on mine they are the same as later models. the last digits on the vin are 2GA000778 and it is called a canadian import. I was wondering if being an early number like that if they could have used parts from different years? Any ideas?