Neither of the boats pictured in the Craigslist ad looks like a Necky Looksha sport. the yellow one is a Perception brand boat. The green is unknown brand and looks to be from the 90s (or maybe even 80s).
The Necky Looksha IV and Sport are ruddered boats, made from the mid-90s to mmid-00s. The Sport is primarily a 14.5’ long version of the 17.6’ IV. Both of these boats are good for larger paddlers. My first boat was a Looksha IV and second was a Looksha Sport - had these back in the 00s when I was 6’ and 215 lbs (and still fit even now at 225 lbs. They stopped making the IV/sport by mid-00s, so any out there are going to be getting old. I find newer boats usually to be more comfortable, one of the reasons I got rid of the Lookshas.
Your weight and height is pretty close to my partner. The boat she has settled on after quite a few tries is a Valley Gemini. She has the plastic version, but they also do make 2 composite versions.
She had a Necky Chatham 16 and a Dagger Alchemy S. Both were a little large for her in the cockpit. She had trouble trying to stay connected to the boat when she was trying to learn to roll (e.g. would fall out when she flips over) and had trouble edging them. If less performance and/or not learning to roll is fine, then a larger cockpit boat would be fine.
From her experience, some boats that fit smaller paddlers:
Valley Gemini
Valley Avocet LV (composite version - the plastic version runs a bit large so isn’t as well liked by smaller paddlers)
Sterling IceCap (win lottery boat, as they are VERY expensive, but oh so awesome)
Necky Elaho
P&H Scorpio LV
Necky Lookshga IV LV (rare beast - only seen one in my life)
The following should work, but might be a little large if you wanted performance (rolling and strong edging):
Necky Eliza
Dagger Alchemy 14.0S
Dagger Startos 145S
Jackson Journey 135 (and maybe the 140)
Northshore Atlantic LV
Necky Chatham 16
I’ve heard the Current Designs Karla is good for smaller paddlers, but we haven’t confirmed that. The max capacity they list makes me question that,
In general, you will want a boat listed as low volume (LV) or small. One made for average or large paddlers you will bee swimming in.
If you haven’t yet, what you may want to do is find a specialty kayak outfitter (not a big big box store) and take an intro to sea kayaking class. Some may be repeat with what you have learned in the past, but the instructors should be able to work with you on what boats are around your area (and probably try a few boats while you are there) that would work for your size and needs and ensuring you know how to self rescue a sea kayak could come in handy at a later time.