the roof has more of a sag than most....but there's no opening in that section so it just might be that the section of roof was maybe a little thin and in the curing process developed a concave shape.....as long as it keeps the rain out who cares (you said the ceiling on the inside looked fine)...........leads to my next point
from what anecdotal information I've been able to gather there was a definite change in direction/build practices when BFs went from being "17s" to "1500 series 17s"...that happened some time in the mid 1980s looks like....and coincided with the appearance of rockguards with gas shocks INSIDE the rockguard (as opposed to a flattish rockguard with springshocks mounted on the outside of the rockguard....visible when closed up)
the all fiberglass two piece bathroom also seems to have made its first appearance at the same time but not sure.....
one thing is for sure in 1983 you could buy a 17 with or without a hot water heater (with a shower or not)... some seem to have come out of the factory with toilets and some with porta pottys ...it was all over the map options wise I think....they never seem to have the full awning
gear either...just that track at the top curbside....
after that "break point" in the mid 80s...things seem to have gone in a different direction....all trailers built with the same options...except maybe AC....all of them had the full awning
and hardware (from AE)
might be just me but I suspect that the FG schedule for the molds was upsized as well.....because I've seen some straight "17s" listing dry weight
as below 2000 lbs....later models (1500 series 17s) tend to list 2200 to 2400 dry weight
but who cares about all that....looks like you got a real good deal....whatever money you decide to put into this thing you will get it back...at the price you paid
when I was shopping a BF owner told me: you can buy these things for "X"...spend one or two grand to get it to just what you want to be and in 4-5 years sell it for "X" again......I tend to agree with him and I would think you would do better than most in that department given your initial outlay
congratulations....you just bought yourself a great hobby...lotsa fun
where in BC are you located anyways????