The six thatchers. Series 4. The fake series we call it. If we go by the John's tab theory... wait no that's only for tfp. Well then if we go by the emp theory (which is getting weaker the more time passes) then The Six Thatchers makes more sense. If this is happening in somebody's mind, idc who's, then TST could be a mental construct. John has a blog post that detailed some guy killing his boyfriend & hiding the murder weapon in a Thatcher bust, then going around smashing them to get it back.
The exact same thing happens in TST, the blog post and episode even have the same freaking name. It was posted during ASIB times. If this happens in Sherlock's mp, then it could be that he was reading John's blog (which he was) and he created the Ajay story while reading that post.
I'm just scrambling for sense. Why would mofftiss use the same trope, same bust, same title twice? It's way too similar. If they were both references to the same ACD canon, I could understand, but they're way too similar for that.