Mr Horsnell, 62, who served in the Royal Artillery, was on a fundraising fishing trip for the veterans’ charity when the ring was taken.
He said: “I was gutted when it was stolen as it was nearly four years to the day when my fiancee Tracey died.
“I was literally physically sick when I noticed it had gone, I couldn’t believe it.”
The thieves took the ring, a charm bracelet, some cash, a tablet computer and a valuable chess set on 23 September.
It prompted Mr Horsnell to post this appeal on social media: “The most precious thing I own is the engagement ring I gave to Tracey on my 50th birthday which always laid by her ashes in the living room.”
