Coop Assessments and Contributed Capital on Home Office Deduction form 8829

[NYRon]

I am a coop owner and use my apartment for bookkeeping and billing.

1. Can I combine coop assessments (not earmarked) with my monthly maintenance on form 8829?
2. On what line should maintenance charges be listed? line 20?

2. My coop has sent me a letter that says "Amortization of mortgage principal and assessments for Capital Improvements constitute contributions to the capital of the chord variation in may be added to the basis of your investment."

1.  Can I add these annual amounts to my apartment's adjusted basis on line 37 of form 8829, calculation of depreciation? 
2. The form instructions say: "Attach your own statement showing the cost or other basis of additions and improvements, used at least partially for business, that were placed in service after you began to use your home for business." Should these capital contributions be included in such a statement? Does the statement need to reiterate every year since I used my apartment for business purposes?
3. Is there is an issue in including unearmarked assessments with maintenance (assuming I can), given that they might have been used in part for these capital improvements?

[NYRon]

Addendum: The assessments went to the reserve fund.