MK3 2.0L Brake Servo replacement/alternative?

[Gollum1980]

Hi folks,

Posting on behalf of an elderly couple in the village who run a MK3 Transit 2.0L (converted camper?) ... It is clearly their pride and joy.
They've had brake problems and are currently driving using the handbrake (crazy, I know!)
After taking it to the garage they've been told the brake servo is knackered and that another part is not available. After searching the internet, I've not been able to find anything other than a Bosch replacement that nowhere has in stock.

Is there an alternative, easier to find servo that'll fit in its place? Can anybody point me in the right direction? I know little about transits but I'm a classic Ford fan and would love to see this stay on the road!

The reg is F584 THD and the servo is silver in colour and has the numbers "L26EE and LBDM2F001B5" on it.

Regards!