#1: 100-125# at the most
#2 yes they make both, pin off and bolt on
#3 yes you can keep them, the speedo is mechanical, and tach doesnt matter and tach is ran off the coil
#4 im sure there is, dont know any off the top of my head
#5 the usual stuff, no signs of wreckage or abuse, northern car, there are slight differences over the years between cars, its mainly personal preference to some ppl. I happen to like 91-92 the most.
#6 only way I know is the acutal size is different.
When I was looking for one, there was a very optionless 88 blue coupe at the corner of westshore and kennedy. Guy wanted a bit much for it, but it was in fairly nice shape. It had no options other than cruise control and a/c