My Eddystone 750 has a 6BE6 heptode as first mixer (V2).

The schematic I have shows it as an ECH42 triode-pentode.

It's hard to tell whether it's original because this is an old, hacked
about radio. It's quite a late 750, the serial number suggests its a
1955 model and I know that other models of Eddystone use the 6BE6, so
it might have been a production change.

Anyone know whether its original or a later modification?

Cheers
TW