letters on a headstone .. ESO.M.R.E.A.H.R.H.S. ***completed

[eadaoin]

William Austin's grave has the letters above after his name.
I'm only recording his headstone, so I don't need any information on his family, life etc

He was was a gardener in Gosford Gardens, East Lothian, at the time of his marriage in Dublin, so maybe RHS is something like Royal Horticultural Society?
Could anyone hazard a guess at what the other letters might be? I'd be most grateful, as I'd like to group them properly in my transcription.

[aghadowey]

First 3 letters E.S.Q. [Esquire]
Next 3 letters M.B.E. [Member of the Most Excellent Order of the British Empire]

[eadaoin]

Thanks, Aghadowey,
I missed the tail" on the Q, and the bottom of the B. (and I got new specs very recently!!
So it's just A.H. that I have to find out.

[aghadowey]

Where was the gravestone and when did he die?

[eadaoin]

Kilbarrack Cemetery, Sutton, Dublin 13. I've been recording it for the last three years. My current "avatar" is the old church in the graveyard.
He died in 1980, and I've seen his burial record.
I looked at his marriage cert  in Dublin in 1920, which is where I found his gardening background.

[KGarrad]

R.H.S. = Royal Horticultural Society.

[eadaoin]

Thanks KG,
I felt it might be that.
EDIT: I've just found A.H.R.H.S. = Associate of Honour of the Royal Horticultural Society.

Thanks again, Aghadowey and KGarrad.

[KGarrad]

My grandfather was a member!
Shame he died before I was born?

[heywood]

“ Associate of Honour

Established in 1930, the Associate of Honour is conferred on persons of British nationality who have rendered distinguished service to the practice of horticulture during the course of their working life.”

From here
https://www.rhs.org.uk/about-the-rhs/who-we-are/rhs-council/rhs-awards