1) Shelved shares don't exist as BTC anywhere. They've never been mined. Actual funds are not anything to do with shelved shares. And again, while unrelated to shelved shares, looking at the balance for cold wallet addresses isn't useful, since these wallets are used for other purposes.
1) They do exist as an amounts in BTC in the Eligius database (PPS part of CPPSRB).
Shelved shares, the payout queue, the minimum payout only define the order in which those amounts are converted to actual BTC when the pool mines a block.
The reason for my question was to try to estimate how far/close recent shelved shares are from a possible payout. That information is not visible on the user stats page.
If there are some extra funds on the Eligius accounts that are meant for miners then recent shelved shares are probably close and probably would be visible on the user page after the next manual payout.
If there are no such funds then I would guess that recent shelved shares would stay invisible for at least a month.
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2) According to the numbers above, for the pool to be able to pay for all shelved shares the pool needed extra 25 BTC (55 BTC - 30 BTC) or basically one mined block. Is it correct?
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2) The payout queue includes estimates for the current round. So let's say the payout queue is at ~55 BTC. The pool finds a block, 25 BTC is paid, and then estimates for the next round are included again bringing it back to ~55 BTC (+/- depending on who's still at/above minimum payout).
This was another question with the same purpose.
If the answe to it is 'yes', then it would take 1 or 2 lucky rounds for recent shelved shares to at least appear on the user stats page or even to be converted to actual BTC.
If the answer is 'no', than I don't understands what you included in 30 BTC and 55 BTC.