1970 dodge dart seatbelts

wondering if anyone can help?

i have none in my car so i have no idea how they are supposed to work.

looking at the pictures on the internet of the belts just confuses me as there seems to be lots of individual belts, and i cant work out whats what.

these are the type i was thinking of.

http://www.ebay.co.uk/itm/1970-DODGE-PLYMOUTH-MOPAR-DART-DEMON-DUSTER-ROAD-RUNNER-SUPER-BEE-RT-SEAT-BELTS-/200820677611?pt=Motors_Car_Truck_Parts_Accessories&hash=item2ec1d85beb

how ever, from what i can tell you have a lapbelt and a sholder belt (sholder hanging from the roof, and the lap from the side of the seat?

do these clip into two different buckles? or 2 into 1?

whats the really tiny belt ontop of the retractor units?

Thanks for your input.

(pics would be a massive help too or if you able to tell me what belt is what in the picture)

:)