Chickens stopped laying.

Just read Cara's Poultry Pages Newsletter (October), in particular the last subject 'Laying slowed down'.
I have three hens, one is a rescue hen, and only ever laid a few eggs since we got her, the other two, a black rock and a maran, were both excellent layers, giving us about 5 or 6 eggs each per week.
The newsletter states that around this time of year, with the dark nights coming in, hens may stop or slow down production.
The last eggs we got from ours was on the 27th July. We live in Ross-shire, and had daylight at that time until 10 or 11 pm. It's now around 7.30pm when it gets dark.
The hens are healthy enough, eating, drinking as they always have, with layers pellets, grain, grit, oyster shell, ACV in their water, wormed each month and have the run of a large garden.
Around the time they stopped laying, the two layers did attack our rescue hen, making a real mess of her, but she survived with a bit of care, and now they all get on as normal. They are also about two and a half years old. Don't know how old the rescue hen is.
So, are they too old to produce eggs? Will they start producing again? I don't think it is anything to do with sunlight, but could it be something to do with the attack on our rescue hen?
Finally, what do you do with three hens have not produce an egg for almost three months now, yet still require the care, maintenance and costs, to keep them as 'pets'?
Sounds a bit harsh, but two neighbours (heartless sods!) who both keep hens, simply say get rid of them!

I only usually keep two or three chickens at a time, but I'd never get rid of one of my girls simply because they have stopped laying. They don't cost much to keep, take up little time, and I feel that after laying eggs for a couple of years or so they deserve their retirement.  They are very entertaining and have their own personalities, and so far, my 'elderly ladies' have passed away peacefully with old age.
I know not everyone feels like this, and each of us has to make our own decisions as to what to do when they finish laying, but one of the reasons that I started keeping chickens was that I was appalled at the way the majority of commercial chickens are kept, and like to feel that my girls are treated with kindness and respect.
I've only got two at the moment, and Daisy has finished laying now, so she is being retired and we're off tomorrow to pick up a couple of 'new girls'.

We have mostly ex-commercials who may or may not lay good or frail eggs, but us being rather soft they live the life of Riley till they die. One thing I will say is they are the only ones who lay through the winter, not prolifically but enough to keep us going with eggs and the occasional half dozen for the neighbours. But we have eight and they are giving us four or five eggs most days, On the other hand, the two backyard and the pure breds stop laying late summer with the moult and rarely give us an egg till around February. So, like your's Snowy, our non-commercial are living the good life, eating and being ladies of leisure till next year, while the commercials who have worked very hard before we got them, keep us in eggs all year...except the ones who have given up laying.

Complicated or what?