Suggestions please...

As well as Wiltshire foods there is "Cook" which can be ordered on line www.cookfood.net

Also "All Plants" provides some really lovely vegetarian options

allplants.com

Wiltshire foods have been great for some of my elderly relations. They say the meals are very tasty.

There are some freeze dried ones in packets that come once a month, I think. I can't remember the name but will post it when I find it.
You might send him a month's supply to try perhaps, if you can afford it?

Another vote for Wiltshire meals. My mother had them for some years and I seem to recall a vast selection, for every taste and level of appetite.
If they don’t have them already, could you get a brochure sent to them?

I think Wilshire also do meals for two in some cases.
And some nice desserts, too.

Can you get him involved in meals on wheels or one of the local groups that does meals My Dad had Wiltshire foods for many years after mum went into residential they are very nourishing meals and just need a few minutes in the microwave There is huge variety too chose from they were delivered once a fortnight and he just used to pop it in the microwave what ever he chose for that day They also cater for allergy etc etc when he got to his last couple of years he had a local I think it was called Grannies kitchen or something like that and they delivered them hot every day at the time of his choice and weekends he used to have a tea as well it was really good value and he loved the ladies coming in everyday for a five minute visit when they brought his tray of food