LB10501BA xx is a common cathode display as per http://www.lightbo.cn/pdf/19LB10501EB.pdf
. Presumably a pack of 3.
If you wished to read his through a Pi you would need to solder 1 + 7 + 1 + 3 (GND + 7 segments + dp + 3 cathodes ) = 12 wires to the board. It is likely that the voltages exceed the 3V3 of the Pi pins so most would need some form of level shifter. These wires would be read by the Pi pins.
So can you get to all the pins? Can you determine the voltages - warning a multimeter will not work here, you need to either measure using a scope or determine the voltage from examination of the circuit - starting with the value of the power supply rails.
To actually decode the display you need to understand the way these displays are driven - almost certainly it will be multiplexed.
All this sounds a bit much unless its more of a learning exercise than a practical one. There is every chance of killing either the Pi or the display along the way.....