Accounting For Insurance Claim Proceeds

I am looking for someone who has practical knowledge of accounting for insurace claim proceeds for a fire loss. 

In general, it seems that assets should be written off at a loss and the cost of replacement assets written up as a gain.  Reimbursed expenses would be a wash.  Business interruption/loss of income would be a gain.

But if a claim hasn't closed and the company has not yet purchased all of their replacement assets it seems like this is a moving target.  Or if you have to make an assumption of what the payout would be and are wrong then an adjustment would be required in a subsequent period.  This would also require setting up a receivable. 

Since business interruption/loss of income relates to a period of time, does this portion of the insurance proceeds get reported during the time period it applies rather than as the time of the loss?

For cash flow reporting the insurance advances must be identified as either related to investing or operating activities.  Since advances are not defined as to coverage, any priority as to how to assign advances against replacement asset purchases or expenses or loss of income?

Also this company has a triple net lease and some of the insurance proceeds go to the landlord and it covers multiple property locations so the max policy amount will not apply - only a portion based on the properties covered and then only a portion of that since some (most) of the insurance money is for the landlord to rebuild. 

Also, any general rule for the book versus tax treatment?

Thanks so much.