Looks to me it's this bulb 5 watt lw scientific bulb . Also found a this one on Ali express it's looks the same but I'm not sure aliexpress link
As it is a Fluorescent bulb you probably can't just retrofit leds to the contact as there maybe is a starter for the bulb. Probably best way is to use a multimeter and take some measurements around the lighting circuit(please be careful as this needs to be done when it's on). You then probably need a some transformer to get lower voltage and DC.