Driving LEDs designed for 380mA at 350mA will be fine. The output is more or less directly proportional to current in that range, so you'll lose about 10% brightness.
Ultimately decided on a replacement light as the driver was 50% of the cost and not guaranteed to fit in the space, or indeed be the actual cause of the flashing
This light is flashing. I'd guess probably the power supply failing.
I haven't found a PS available from Eternal, or another elsewhere with the same 380ma constant current 48V. 350ma exist
NN8 6AB is their postcode, so a red herring as far as part numbers.
Any pointers for a suitable replacement, or fix.
Thanks
Neil.