90% This is an original Enduro. The paintwork and the tail lights, the fuel cock, seat cover are not original and of course the rounded kick starter is an aftermarket one. The exhaust sound is perfect. Also the year is correct. 1982 was the first year when Enduros came out. This is from 1983. The first ones came in silver. After they released the light and dark green, red, and ocher yellow ones.
Beautiful! I had a Silver S51 Enduro (UK Version) back in the early 80’s. Apart from the sidestand mine was identical to this one. The later Enduros had a different front fender but the earliest ones were like this.