Hi @bobekas,
For testing the upgrade, trying to expand a bit on the forum post on upgrading the ledger suite, you could set up a test canister (either on mainnet, or in a local development environment using dfx and pocketic), create a representative number of transactions so that it as closely as possible reflects the production ledger, and then go through the upgrade and verification steps.
Regarding the WASM version - I’m not able to find the WASM that is installed.
IC_VERSION=2e3589427cd9648d4edaebc1b96b5daf8fdd94d8 refers to a commit from October 2023. However, when querying the git_commit_id from the canister (using dfx canister --ic metadata wqihv-qyaaa-aaaak-afjoa-cai git_commit_id), I get 794fc5b9341fa8f6a0e8f219201c35f0b5727ab9, a commit from May 2023. Neither of those WASMs (.gziped or not) (2e3589427c, 794fc5b934) have a sha256sum that matches the currently installed module hash of c393527a9068184267e1f845188bae58b13e0140b119c36145a0eff2cf9610bd. Do you have any more information on how you installed the WASM? E.g., the date you installed it, if you installed it using a script/which command(s) you used, did you build the WASM yourself (if so, how) or if you downloaded a pre-built WASM?