Need new depth sounded disp!y ONLY

[deltaten]

!little 2" gauge w/ 3/8" LCD has gone TU. Sunburned and fogged, way too small anyway. I'd like to replace the head unit only, as the sensor is well pasted in about the only position.
So, what will work with an Airmar 79s ,has (minimum) 3/4" digits and is available separately ?
Have rummaged through derelict and wreck-outs for several years here in the yard with no joy for salvage/used units. The few times searching ebay, same result.I
Could someone point me in the right direction please?

TIA,
Paul