68 Beetle - New Owner - Gas heater question

[Scoooooop]

Hi there, I bought a 1968 Beetle yesterday and I'm trying to figure out why the fuel line is split after the fuel pump, one line going to the carburetor but the other going back into the firewall and into some kind of regulator behind the rear wheel. It's single carb and I'm wondering if I'm looking at the remains of a gas heater connection? There isn't one now but the heat exchanger plumbing looks odd too, as far as I can tell it's feeding directly under the rear seats and the two rear ends of the heater channels are connected.

I can't find any information online about how the gas heaters are connected - I'd like to remove the extra line and reconfigure the heating but I want to know what I'm looking at first! Can anyone give me an idea why it's set up this way?

Thanks

[Bruce.m]

Not seen that before.
The original VW gas heater was mounted in the front & used a separate pulse fuel pump connected to the tank. So that isn’t original VW.

[Scoooooop]

Thanks Bruce.

I'm only guessing gas heater as I don't know what else would have needed the extra fuel line. It's really stock and I seriously doubt that it ever had dual carbs. Thanks for your help, I'm going to remove it and see what happens.