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.
Still not sure what you're getting at. The payout queue and CPPSRB rewards (which includes handling of shelved shares) have pretty much nothing to do with each other. The payout queue is just Eligius's way of processing payouts in the coinbase transaction of blocks. It's not required for shelves shares/CPPSRB/etc. They're completely independent.
The funds actually in the Eligius offline wallets (NOT necessarily the balance you see for various Eligius related addresses) is generally due to miners AND is reflected in the payout queue. Again, nothing to do with shelved shares since if the funds exist as real BTC anywhere, then the related shares are not shelved. If it's in the payout queue (before estimates), it's not shelved. Again, the two are not related.
Shelved shares also do not exist as amounts in BTC. They are stored as a portion of the block subsidy for the difficulty at which they were mined. (Not going to get into the details of that, but feel free to dig back 3 years or so to when the last reward halving happened for that discussion.)
There are never any "extra" funds, either. If there are funds due miners that Eligius has, then the payout queue has grown by that amount as well. Any funds Eligius has in its offline wallets due to miners have absolutely nothing whatsoever to do with shelved shares.
This has all been explained many many times. I'm really unsure where the confusion is.