Honey gets hers in one piece - and has done since she was about 14 weeks (when we gave her her first one!).
From reading your posts here and on BritBarf, I do think Merry has got you very well trained....
I have a lot of sympathy - Honey has recently started a bit of "playing" with her food - we are just taking a (reasonably) firm line with it - we don't let her outside with her food, so she can't bury it, and we restrict her to one room, so she can't drag it around the house. If she wants to stop eating we then pick it up - we do offer her it again later, but it is always the same meal. If she still doesn't eat it she gets it again as the next meal. As it is raw, we can't carry it over further than that, but she doesn't get given alternatives if she hasn't eaten.
The only thing we are struggling to get her to eat is liver, but if it is something we know she eats, then she can get on and eat it, or do without!
I do think teeth and age may be having an impact - Merry's appetite is probably changing as he changes from growth spurt to a slowing of growth - I know Honey's appetite has decreased recently, but it also decreased a couple of months ago....
I would feed a basic variety of BARF meals you know he eats, and stick to your guns.