Great Western Coffee Shop

I know at one time airlines(British airways?) use to show at least nine seats available on long haul

"SOME" football clubs are showing "seats available"

Would any TOC actually show a map of the coach/s where seats are actually availble

Do you mean 'unreserved'?

Because many tickets are flexible & thus any train may be full of passengers, even if seats are available.

Yes unreserved.

The answer is ‘no’, simply bevause the amount of time & money needed to keep these up to date / linked to stock number (what happens if the original stock breaks down & gets replaced say, en-route?!) to is far to much for the number of people that would actually use it! Don’t forget you can reserve with 10mins before departing any station too, so it would only be accurate for the moment you accessed it.

And XC always keep many seats unreserved. Even from the 10 min reservation system

I don't think there would need to be much time and money needed.  I can tell you exactly what seats are reserved and where from and to on all GWR services, and I imagine CrossCountry employees have access to the same information for their trains.  Putting that into the public domain would be pretty easy - even if the 10 min system might complicate things a little.

I agree however that it would be of little use to most people.  A better system is to give a broad indication of how many seats in each carriage are reserved - I've seen those on some station displays for CrossCountry services.

Even better than that is actual live loading indicators which some operators including Thameslink and GWR are now starting to introduce, though there is fine tuning work to be done and the trains have to be fitted with equipment to provide that information.

I had an enquiry recently from a friend who purchased their '2 Adults and 2 children with Family Railcard return from Exeter SD to Derby' from a well known online retailer.  They had mobile split tickets (unknowingly) and each person was required to change seats twice during the journey. What was more worrying though is that the party was split across three coaches! Surely the online booking system can put people together or at least warn them that seats cannot be booked together. Having been advised to visit a manned ticket office, they were able to get seats together for the whole of the journey (although the ticket office was unable to guarantee this until attempting to book)! 

Depends on the request made by the third-party software to the TOCs reservation system. It may not have been a grouped request.

I would hope that ANY software would assume such a request to be a grouped request.  If not, then even more reason to not outsource ticket bookings!

I have done three return journeys on Cross-Country Reading to Manchester and my randomly reserved seat in first was never the one I wanted (Coach A). Because of the 10 minute reservation system I do not change to another unreserved desirable seat as I could get turfed out of it at the next station. My solution has now been to find a seat in the other half of the two-set train which is unreserved (Coach G) and more importantly - unreservable - so I can stay put where I am. I take full refreshments with me as five out of the six journeys there was no trolley service in the second half.

The GWR app gives loading indicators for IET services but as Industry Insider says it does need some fine tuning on occasions.

(http://www.mbob.co.uk/rforum/gwload.jpg)