Xword reasoning help please

[cracker22]

Three whose reasoning I can't work out. Help please:

DM 14284 4d: Small opening for wary Scottish nurses (Registered) = CRANNY

DM 14281 18d: Coin made of copper essentially? = TWOPENCE

[Mamyalynne]

Wary = Canny around (R)

Cranny is a small opening

[Psybbo]

canny + r

[boxtops]

Nooks and crannies, mamya :-)

[Mamyalynne]

Copper has two 'P's' in the middle - essentially

[Mamyalynne]

Or crooks and nannies boxy :-)

[boxtops]

LOL (I like the Ps explanation too!)

[Psybbo]

Love it, but don't take the ps

[Mamyalynne]

Well I like my answer Methyl.

[boxtops]

I think mamya's answer is right. The two pence coin is what most of us call a copper coin, and the 2 ps (as Mamya says) are the centre (essential) letters of the the word.

[elliemay1]

You said 3 that you couldn't work out, what is the other one?

[Psybbo]

mamya, you're going to have to spell it :-)

[Mamyalynne]

IT??

[Psybbo]

Ihat's my tuppence worth!

[Mamyalynne]

No worries only having fun, promise.

[cracker22]

Yes, it must be the 2 Ps in the middle. Thesaurus.com has ...at the heart of, centrally... for "essentially", in which case it is rather a good clue, albeit a bit too tricky for me to get!

I started with three without the reasoning, but I got the other one while typing it in.

Thanks all.