We had a neighbour with a 1700 it had strait door have only seen 1 with that door and the 1500 have only heard of one other. The models of 15' and up all seem to be all in low numbers. Was told only 400 17', 17.5' and 18'. Was told 18' is rare like yours.
Hi: Ijsilver noticed your 1500's awning looks to be roll out and has arms do you know if original? Our 1700 came with roller awning and curved arms from factory. We even have a copy of the original options list and 1978 prices. Have never seen a 1500 in our travels or another with roll out awning.