[HELP] 2015 blockchain.info non-HD wallet — change addresses and dates hi

[Geofingerprintgeo]

I have a blockchain.info v2 wallet from 2015. I backed it up
only ONCE after creation and never updated it. Over 2 years
I made 50+ transactions. Each transaction created new change
addresses. Those change addresses are NOT in my backup.

THE STRANGE BEHAVIOR AFTER 2020 MIGRATION
Before 2020, when logging in:
- I could see ALL transactions with FULL dates
- I could see change addresses and their balances
  (~0.3 BTC on one, slightly less on another)

After blockchain.info's 2019/2020 migration:
- Change addresses disappeared from view
- ONLY original 16 addresses show up
- Even on those 16 addresses, NOT all transaction dates
  are shown — some transactions are completely missing
  from the UI
- The wallet displays "0 balance" and incomplete history,
  even though the transactions still exist on-chain

This is not a "missing device" case. The blockchain data
is there. The wallet interface simply does not display it
anymore.

DETAILS
- Wallet: v2, PBKDF2-SHA1 5000 iter, sharedKey + guid
- NOT HD. No BIP32. Only "keys" array
- Backup contains 16 original keys only
- Change addresses still exist on-chain (I found one by
  tracing outgoing transactions)

ABOUT THE SEED
I never had a seed phrase in 2015. I only obtained the
wallet's "recovery mnemonic" this year (2025).
Try to generate address from seeds like blockchain , we found only the laste
Transaction 2022 any other , and segwit address

WHAT I'VE TRIED
- BIP32/39/44/49/84/86 with all passphrases — no match
- Randstorm (4 PRNGs, ±1000ms around created_time) —
  no match yet

QUESTIONS
1) Did other users lose change addresses AND transaction
   dates in the 2020 migration?
2) Can I still request legacy wallet data export using
   sharedKey + guid?
3) For one specific known address with ~0.3 BTC, is Randstorm
   realistic without a GPU cluster?
4) Has anyone actually recovered a change address from a
   non-HD blockchain.info wallet?

I accept this may be unrecoverable. Just want honest technical
answers, not recovery scammers.

Thanks.

[DaveF]

https://btcrecover.readthedocs.io/en/latest/TUTORIAL/#downloading-blockchaincom-wallet-files

[Geofingerprintgeo]

https://btcrecover.readthedocs.io/en/latest/TUTORIAL/#downloading-blockchaincom-wallet-files

i try this no result