Just something I thought of just now:
You say that dealing with transference can be about noticing patterns that relate to things in the past and then understand that topic.

Now, I might be wrong, but since your T is not very trained in these sorts of things, maybe it's hard for him to go 'haha, this is the same as you did with X' and then get somewhere with that? If I go to my T and I talk to him about how much I miss him, or that I'm scared that he might die, he won't just go 'okay, but let's talk about how you missed your parents when you were a kid'. That would just be hitchhiking my session. It should be what you want to talk about, right?

So if you go in and say things about your transference, he probably tries to stick with that topic. He either doesn't see the things in your past that might be similar, or does, but doesn't want to just bring them up randomly. I'm not sure how much you talk about your past vs. about what's happening right now, but it might also be that your T cannot notice patterns because he does not have that information yet. It's hard to notice patterns when you don't know about any of the other things that happened.

So, if this might be true, it might be a good idea to think yourself about why you are reacting the way you do. You don't need a complete theory, but like instances where you felt similar (maybe other than ex-MC, because I think that topic is difficult for him, for whatever reason). And then instead of just saying how you're feeling in regards to your T, also mention where that might stem from and then discuss that past stuff?

I might be completely wrong, it's just an idea.

Oh, also regarding transitional objects/showing things: I've never shown my T any pictures or anything like that, but that's just because I'd rather have him talk to me for an hour than looking at pictures. He tends to get very absorbed in whatever we do. However, I'm 99% sure he'd be okay with it. I think with your T, the issue might be that he doesn't know how to deal with the stone thing properly yet. I can imagine him thinking that if you guys listened to the recording together, and then he said something about transitional objects, it might be hurtful or similar for you, and he can't tell because he doesn't really understand the topic.