Odd Proof Sovereign (1887)

[SohoMint]

Another post from me AGAIN!
Early September I went to the RMM to study the tooling and coins of 1887. Obviously, there were some weird things - that is why I am studying such pieces (and slight influence by Andrew Thorburn, he knows he caused this). I cannot, for the life of me, get this Sovereign out of my head that I saw.

For context, the RMM had two proof sovereigns in gold (three if you want to count the reverse only uniface but not important). One sovereign had, the standard features you'd expect of a proof. Clear, shiny, reflective fields and muted matte design and legend. This was the same on both the obverse and the reverse - for those curious RMM 3785. The second piece, RMM 3786, had the same features on the obverse, mirror like fields, matte like portrait. The reverse caught me off guard though. The whole thing, shiny. Not just the fields, there was not a trace of matte-like features on the design or date! It was really uncanny, obviously not all proofs have matte-life features, but the fact that one side did and the other didn't felt weird to me. I don't know how else to describe it. It felt intentional, especially when compared to RMM 3785. You can find links to both coins at the bottom. Am I crazy? Is this normal? I will admit I am not the most experienced in proofs - but I will blame my lack of experience on my age (I'm only 18, I can only know so much!) It was such a striking distinction between the two pieces. Any insights, references or just comments would be GREATLY appreciated so I can get some proper sleep tonight instead of thinking about this damn coin! I've attached a photo, though not the greatest one - it is so hard to show what I'm talking about out of hand. 

https://royalmintmuseum.collectionsindex.com/object-rmm-3785
https://royalmintmuseum.collectionsindex.com/object-rmm-3786

[Coinery]

If the coin to the right is the shiny version you speak of, you can’t rule out polishing or cleaning of some description? Your photos highlights hairlines running in multiple directions, seems odd for a museum coin, which was presumably taken  into its collection straight from the press?

[SohoMint]

3 hours ago, Coinery said:

If the coin to the right is the shiny version you speak of, you can’t rule out polishing or cleaning of some description? Your photos highlights hairlines running in multiple directions, seems odd for a museum coin, which was presumably taken  into its collection straight from the press?

Perhaps, but even the non-shiny one features the same/similiar hairlines across the fields - which could very well be a property of die polishing or even a treatment of the blanks before striking. I also would expect that polishing would cause damage to the design, creating weakness to fine features rather than just removing the matte texture, yet the design is fully intact and very sharp. I am trying to get my friend, who has a PhD in material sciences, to have a look to see if he can determine if this is a production or post production property, so fingers crossed he can find some time to do so.

[Coinery]

I 100% understand your point, though I have to say the fine ‘lines’ on the right-hand example look very different, and very suspect to me.

Commendable that you’re embracing numismatics at this level, especially for someone of your age. Excellent stuff 🙏

[SohoMint]

2 hours ago, Coinery said:

I 100% understand your point, though I have to say the fine ‘lines’ on the right-hand example look very different, and very suspect to me.

Commendable that you’re embracing numismatics at this level, especially for someone of your age. Excellent stuff 🙏

Wait are you The Coinery, as in, the one that sold that Edward VIII penny and who currently has the 1808 Unique Penny???