I am still knocked back on my heels, having stumbled across this post as a result of an idle google search.
I have always felt a strong link with Reginald Badger as, after he died in 1957 his widow Betty married my grandfather who was a recent widower himself. My grandparents and the Badgers had been friends together for years, so when each surviving spouse found themselves alone, I think they felt it only made good sense to continue their adventures together and get married.
After my grandfather died, I was lucky enough to stay with Betty at Biddlesden Park many times during my teen years. We discussed all sorts of topics, despite her being in her 80s and me being teenager hitch-hiking to see her. She was a remarkable person, and I always got the impression that Reggie was great company as well.
Betty and Reggie were married in 1923. He was 41 and she was just 23. Of course many of the men closer to her age had been killed in the war, including two of Betty's brothers. Reggie and Betty bought the beautiful Biddlesden Park in about 1932. They never had kids of their own. Given their mutual love of horses, they ran a successful stud at Biddlesden together, and Betty continued after Reggie died. I won't go on about their family history here, but I can at least probably tell you when the knife you have likely started its journey to your hands.
Betty died in 1985. She left her estate to a nephew whom she had apparently seldom seen for 40 years. He evidently didn't have much interest in family history as he ordered the entire contents of the house liquidated at auction, held on the lawns of Biddlesden. My cousin and I went up to Biddlesden for the auction, thinking we should get some momentos of our wonderful times with her. We were totally unprepared for the scene; it was horrific. Despite my being a fairly thick-skinned 19 year old at the time, it was too much to see our step-gran Betty and Reggie's entire lives heaped onto tables, being picked over during the preview. Even their photo albums from the 1910s through 1940s were in a jumbled pile with a lot number on them. The housekeeper and groom, who had been part of the house for over 50 years since Reggie and Betty bought the place, were in a state of shock. They were deferential by training, but seeing the bullet-damaged saddle that Reggie had been wounded on with a lot number on it was too much for them. My cousin and I couldn't take it, and couldn't bear to stay for the auction, so after a cup of tea with the old housekeeper and groom in the quiet of their cottage, we drove away in silence.
There is much more to tell, but I won't clutter up this site any more than I already have with this reply! I am sure you have discovered things about Captain (later Colonel., I believe) Thomas Reginald Badger that I would find very interesting. Hopefully I have done the same for you. Perhaps we can have a further exchange by email, although I am wary about posting my email on a website.
I must add that I am very pleased that someone with such an abiding interest has ended up with Reggie's knife. He would be amazed that almost 100 years after he departed for France, he is being discussed on an invention even more remarkable than a wireless!
Best wishes,
DLSG