If you're bringing 65k/mon in from abroad then providing you're from a country that doesn't issue income letters (i.e. UK, US, Oz), Immigration have no right to ask where it came from.. . If you are from elsewhere you need a letter from your embassy confirming you have 65k bt equivalent per month of INCOME (although you don't actually need to bring it in to T/L), but Imm may ask you to show proof of where it comes from.
I've previously just taken a photo with my mobile, of my laptop screen showing the "date of next report", and this was acceptable to Immigration when doing my annual extensions.....
I've often made on-line reports that didn't get approved in the usual 3-4 days. I have then gone into the system and cancelled it, then immediately reapplied. They always then got approved within 24hours...
As long as there is no way the balance could have dropped below 800k you will (should be) OK. So if your book shows an "opening" balance of 1MM and you've had less than 200k in total of withdrawals, then you cannot have dropped. But if you've had say 300k of withdrawals, plus 300k of deposits, then you "could have" dropped below - they have no way to be sure so you'll need a detailed statement.
If you've not regularly updated your bank book they normally give a consolidation of the past 3 months, i.e. total ins and total outs, and the Immigration guys can normally work out if you could have dropped under the 800k during that 3 month period. If you "could" have then you'll need a detailed line by line statement that your local branch should be able to provide (for a small fee). If you do need longer than 3 months, they normally refer back to head office and it'll take a few days/week (plus a larger fee).