I am not sure if there is any mileage in sourcing one from Landrover and if the info in thess manuals are of any help

http://www.landroverresource.com/docs/R380_Gearbox_Overhaul_Manual.pdf

http://mgcontact.free.fr/lounge/brv8/AKM7225EN.pdf

Also this forum's comments may help

http://www.classicroverforum.com/viewtopic.php?f=1&t=11602

Once you have found an equivalent car model then looking at Ebay seems to be a good place to look for the Speedo.

Base on this website, R 380 gearbox seems to be used on these marques

SPEEDO DRIVE OIL SEAL CAR LT77 R380
Oil Seal Kit For The Speedometer Drive Gear On Car Applications Fitted With 5 Speed LT77 or R380 Gearbox.
Fits Car Applications with LT77 or R380 Gearbox
Kit Cars
MGRV8
Morgan
Rover SD1 5 Speed
Triumph TR7 5 Speed
TVR

http://www.shop4autoparts.net/Triumph/Gearbox/aau2304ck-spdoo-drv-oil-seal-kit-car-app.html

thumbs Frank

http://franks4x4-solograndetour.blogspot.co.uk/
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