Technical Any idea what this is?

Has a line going to the intake manifold. I see a sight glass & a filler cap.
Top cylinder lubricator? Some kind of fuel powered heater? Don't think it's some kind of NOS setup, LOL!

 

What is the car?...I think I see a flathead...

 

http://www.mtfca.com/discus/messages/599638/688488.html?1477852516

...it's mentioned as a MMO Marvelous Mystery Oiler in this quoted text at link above...

"Warren, here's a picture of an MMO oiler on my Hudson. I don't know if the stuff helps but it uses it up. There is a sight glass and an adjuster so you can regulate how much it uses."​

 

Gasoline cooler for vaperlock or drag racing..

 

https://www.jalopyjournal.com/forum/threads/marvel-mystery-oil-inverse-oiler.1049972/

@Bird man, here's a thread on it with some great info in the pics...Slinger had an NOS one it seems...

The Company is still in business but the Oil seems to be its business now...

https://www.marvelmysteryoil.com/products/marvel-mystery-oil/

 

I got the same one NOS in a box.
How old is it ?

 

Around 1952 according to the paperwork in Slinger's Thread I shared the link to...but I believe the Mystery Company was formed in 1923 so there may be older versions...