I have encountered a not too dissimilar problem. We sold our house and bought 2 cheaper ones 120 miles away. One we will live in and the other is a refurb and sell on and current combined values �190-�200k. We need around �60k to do them up raised on the home we will live in and hoping the 2nd one is taken into account as it is valued �30k+ more than the mortgage request. I approached a well known broker who said it would be easier to get a mortgage if my hubby got a letter saying he was transferring within his company to the new area (which he is not) and the other house (equivalent to a savings pot) would not be taken into account. Crazy. Having told the advisor I had the letter he ceased contact with me which I have complained about in writing (no answer yet).
I approached my bank. They were marvellous. Saw exactly what I was getting at. Paperwork done next day, valuer in last week, money very soon. And no fees!! No need to prove either of us have employment to go to. Copy of letter taken but I was told we could borrow without it. Now busy choosing fittings while waiting for my funds. Should have gone there in the first place.
Cant offer any ideas to you and just hope your lender is sensible especially as things are storming ahead for you. I always thought (and my bank obviously agrees) that if you cover their risk you get their money.