I had a quick 'visit' on my way home when in the area 2 years ago. I didn't have time to ask for permission to get up close to the stones so I parked a little down the road (near the junction) and walked back towards the farm. The stones are visible from the B4310 between the farm buildings.
We parked by the farmhouse and asked permission to see their stones. The red faced farmer's wife said it was OK, so long as I locked the gate behind me. Upon reaching the gate I saw the reason. A Black Beauty of a horse that wasn't going to leave me alone.
The three stones are all white quartz. Only the central stone is erect (but leaning), and the three of them are not in a straight line. Even allowing for the two fallen stones, ones lying where they fell, if re-erected they still would not be in a perfect line. Perhaps they've been moved? Who knows? Maybe they were once part of a circle, like Duloe in Cornwall.
A description from Coflein implies that Llech Ciste is interpretted, not as a stone row, but as a standing stone with other (suspect?) stones around it:
A white quartz stone, 2.8m long by 1.0m wide by 0.8m thick, now semi-recumbent, having other stones, or boulders, associated with it. The site is no longer considered to represent the remains of a burial chamber.
The name Llech Ciste implies a single stone, the word 'llech' being singular. Presumably the word 'ciste' is to do with the site being interpretted as a burial chamber.
The eight figure grid reference for the site is SN51422832, and the National Primary Record Number (NPRN) is 303977.