SOS - How to interprete this?

In a lovely poem of U.A. Fanthorpe called 'Seven Types of Shadows' I read this few verses:

Or One hundred and fifty-four sonnets! Not bad, Ben?
Or, in the mist and snow, I fancy this might bet he top,
Or I tried it on the dairymaid, and it worked.
Or – surprisingly – We are a grandmother!

The first line is about the 154 sonnets of W. Shakespeare and about his rival Ben Jonson.
The last line is Minister Margaret Thatcher's statement to the press in 1989, on the birth of her first grandchild, Mark Thatcher's son Michael.

But I am still struggling about the other two verses. What is meant by "I fancy this might be the top" and "I tried it on the Diarymaid and it worked"? How you may interprete this? Is it possible that the other two verses are allusions to famous people, too?
May anybody please help me?
Thanks a lot!

Would you be able to post the rest of the poem as well? That might help with context. My first instinct with the second line was "mountain climbing," but that's just pulling it from my gut.

1.
I have an item, Chair, under Any Other Business.
We ghosts have become creatures of habit, with our
Bloody shrouds, bloody footprints, blood. Some of us,
I believe, still hold our heads under our arms.

The agenda ist stale, gentleghosts. Midnight. The temperature drops.
Dogs’ hackles rise. Tawny owls provide.
The continuo. A chain rattles. A floorboard creaks.
We know the repertoire. So do the living.

You see how it is, fellow-ghosts. We are fossilized.
Something unconventional’s needed; the ghost, perhaps,
Of a happy moment. Try this: wraith of a spectral grandee,
Whose horse has just won the Derby. A lady might like that.

He throws his topper in the air, a champagne shade.
Or a musical ghost, ghost of divine Handel,
Scribbling down the final Hallelujah,
Thinking he’s just seen heaven. How about that?

2.
Furthermore, ghosts, the matter of dialogue.
A surplus of vowels is ours – all those ooos and aaas.
Think of the vital things we could be saying,
Like I’ve finished the Pope’s ceiling! All of it!

Or One hundred and fifty-four sonnets! Not bad, Ben?
Or, in the mist and snow, I fancy this might bet he top,
Or I tried it on the dairymaid, and it worked.
Or – surprisingly – We are a grandmother!

>> It's eye-catching that there are quite a lot allusions. There are allusions to Handel, to Michelangelo, to Shakespeare, to Miss Thatcher (UK Prime Minister) but I just can't figure out the hidden meaning of the lines 'I tried it on the dairymaid and it worked' and 'I fancy this might be the top'. Mountain climbing is a good track........

They're all obviously the works of famous people (who died), and what they would say about what they done in life.

The part about getting to the top could be a reference to Sir Edmund Hillary. and the part about trying something on the dairy maid could involve medicine.

Edward Jenner's first smallpox vaccination was a dairymaid

'I fancy this might be the top'.

Mountain climbing, indeed! Maybe the ascension of Everest?