The replies to my question here, however well intentioned, do not address the actual problem i am attempting to solve.

Perhaps i wasn't clear enough in my description of the situation.

The electrum.dat wallet file i have is from around the 2013 period - however, in comparing the seed structure of my wallet to other electrum.dat wallets i have created using older releases of the electrum client from the same period, it appears that the seed structure of the wallet i have is markedly different to the 32 character alphanumeric strings that the other wallets i have been creating present in their wallet files, despite them also being of the electrum.dat type.

The developer of Sparrow is attempting to support importing old keystore type electrum wallets into his project, and has been asking me to examine the structure of my wallet to ascertain how he can go about doing this.

As i have mentioned, the older releases of Electrum i have downloaded (from the 'Previous Releases' Index on Electrum.org ) and created wallets with use a 32 character structure for defining the seed in the electrum.dat wallet file, with a seed version defined as 4, BUT mine, despite being from the same period, does not.

The seed structure of my wallet file is defined by a much longer string, containing several groups of alphanumeric data joined together by plus signs, with an equals sign at it's end - and the 'seed version' of the wallet is defined as 18.

I am attempting to discover why my wallet is so different in it's wallet seed structure and seed version number to the other electrum.dat wallets i am able to create using the older releases of the client.