The H17 Sport was not released until 1990 and it was boomless (well, I think it did have a boomlet until 1995).
To clarify, when the 17 Sport was originally introduced, it was a "boomless" rig. The mainsail had about an 18" long section of Harken traveler track permanently fixed to the clew with a traveller car and adjustment line. This allowed for "outhaul" adjustment of the mainsail. There was no actual boom between the clew of the mainsail to the mast base. Then at some point (late '90s or early 2000's) Hobie did away with the Harken traveler track on the mainsail and introduced the "boomlet" for use on 17 Sports. This boomlet is a section of boom extrusion with a fixed bale to attach the mainsheet blocks. It served the same function as the original traveler track section but did not allow for any outhaul adjustment - lower cost, simplification, and interchangeability from boom to boomless.
The 17SE (single handed version without a jib) has always had a full length boom that connects between the clew of the mainsail and the mast base.
If the boat has a full-length boom and no jib, then it's an SE. If it has a boomless mainsail, a bow spreader, and a jib, then it's a Sport. If it has a full length boom and a jib, then it's either a partial conversion from SE to Sport, or it's got an aftermarket jib kit.