How to light a strip of 32 LCD backlight LEDs
I expect that the supply has been a switched mode constant current supply.
Output 260 mA resulting in a 118 V when all the leds are in series.The open voltage of such a supply is most probably higher.
An LM317HV in constant current mode with a supply of 170 V could be a simple solution but does not solve the inefficiency.
If a high voltage switching supply is difficult you could try to connect the strings in parallel with 4 LM317 in constant current mode ( maintaining 260 mA) for each string and use a 33 to 35V DC power source for all of the strings.
In that case the efficiency would be acceptable.