How do you pronounce 'Leominster'?

I recently visited Leominster for the first time and wondered if the pronunciation of its name would provide the genus of controversy that Shrewsbury does. (Is it 'Shrowsburry' or 'Shroosbery'?)

Of course we are happily familiar with Leicester (Lester) Loughborough (Luffboro) and Towcester (Toaster) all of which still trip up the unknowing so working on that knowledge I calculated that Leominster would probably be pronounced 'Lemster'.

Well, blow me down, I had not expected an exhibit outside the town museum to answer my query so substantially. My next question is, if the town was called 'Lemster' then why and when did they decide to spell it 'Leominster'?

I should have asked the question in the tourist information centre but arriving at the counter I was distracted by the prominent display of a handbill advertising my imminent talk. And at the corner of the street was another.

What a lovely place Lemster is, however they spell it!