Few Near Blocks missing in mainnet but present in testnet and it shows as testnet specific blocks. How to get those block details from mainnet

There are few blocks in near which are missing in mainnet but present in testnet and it shows as testnet specific blocks. Please suggest how do we consider these blocks or get these blocks using the api "https://archival-rpc.mainnet.near.org". Below is the scenario for one of the block

If I try to get the block details of the block 73685420 by using the below curl query:

curl --location --request POST 'https://archival-rpc.mainnet.near.org' \
--header 'Content-Type: application/json' \
--data-raw '{
  "jsonrpc": "2.0",
  "id": "dontcare",
  "method": "block",
  "params": {
    "block_id": 73685420
  }
}'

I get the below output

{
    "jsonrpc": "2.0",
    "error": {
        "name": "HANDLER_ERROR",
        "cause": {
            "info": {},
            "name": "UNKNOWN_BLOCK"
        },
        "code": -32000,
        "message": "Server error",
        "data": "DB Not Found Error: BLOCK HEIGHT: 73685420 \n Cause: Unknown"
    },
    "id": "dontcare"
}

But when I searched the above block in testnet explorer I was able to get it.

how to get the details from mainnet?

Testnet Explorer Block