Identify PCB component from LED circuit

Question

I'm trying to refurb a old pcb taken from a 30 year old cars indicator unit, it's a pretty simple pcb besides one component I'm unable to identify:

You can see it attached to the back here before I took it out and cleaned it up

Anyone know what this is and where I could source a replacement?

Thanks.

EDIT:

Pictures of the back:

Before I started to clean it up:

After:

Answer 1

It looks like a bridge rectifier but I can't think why there would be one in a 12 V DC circuit.

^{simulate this circuit – Schematic created using CircuitLab}

Figure 1. A bridge rectifier consists of four diodes.

There's no scale reference in your photo but I'd guess that's a 1 A device and so is unlikely to be in the actual indicator lamp circuit as these are normally 21 W lamps drawing nearly 2 A each when hot and a lot more when the filament is cold. It's more likely to be rectifying the power for the flasher unit itself.

They're available from any electronics component supplier. You'll find a parameterised search on any of the large suppliers. Select something that's rated for 50 V and whatever current you think is required.