I sense that somehow you have not shopped around for a newer model. Although at first glance, they may appear to be cosmetically more appealing, they may contain many hidden and undesirable qualities.
This is correct, I have not shopped around. Before looking at newer models, I wanted to gauge the value, if any, of the trade.
According to your description, and unless you have made a misrepresentation, the alarm only sounds for diesel fumes.
If not listing all the optional alarm modes is considered misrepresentation, I suppose I did. No harm was intended and I don't think I acted illegally as I'm not selling ... I'm begging.
In my experience, any newer model, or older model for that matter, is programmed to sound the alarm for a myriad of stimuli, including such mundane things as taking a nap, spending too much time on tractor sites, not being attentive, coveting old and comfortable furniture, tinkering with old cars, neglecting to bathe the dog, leaving certain garments in the dryer overnight, etc., etc. I could go on and on.
What? There are others like mine? I was promised by my FIL that I was getting a patented, one-off model. He and I need to have a talk.
Unless you desire an alarm that will sound infinitely more often, I suggest you may want to reconsider or withdraw your offer completely. I suspect you may not fully recognize the near perfection of what you have. I considered making you an offer, since there is no diesel powered vehicles anywhere near my place, but my trade in is considerably older, and in spite of it's range of detection, has become quite comfortable.
Ouch! This really hit home and I feel awful that I made my original post. I will reconsider and edit my offer.
Free – Diesel Fume Alarm
Slightly used, early 1960s model. Not showroom condition, but clean with good paint. Programmed to go off when her car fills with diesel fumes in enclosed garage. Optional alarm modes available. Refuses to park outside. Very reliable and not too bad in the kitchen. I’m the second owner and had her for over 30 years. I will not consider trades. Delivery available and no returns accepted. PM for details.