I have now obtained a copy of the Lease from the Land Registry.
I am glad to say that the Lease is quite clear that YOU are responsible for insuring the property, and only if you do to insure, can the Freeholder then arrange insurance themselves and bill you accordingly. So, you are under no duty to pay this insurance charge of £180.
The Lease also stipulates that you are responsible for paying half towards any maintenance work carried out to the main structure/communal areas/foundations/roof/any fence dividing the 2 gardens. So, if the Freeholder has indeed carried out any such repairs, you are responsible for paying the one half share, with your neighbour paying the other half.
You are of course also responsible for paying the yearly ground rent which is currently £75
(the Lease began in 1983 and the rent was £50 for the first 33 years, which would take you to 2016, and for the next 33 years it is £75).
I hope this assists and sets out the legal position.
If so, I would be grateful if you could rate my answer in the top right hand corner of your screen.