1952 Plymouth Owners? Bolt Size?

Anyone got a 51 or 52 plymouth that can tell me if the original seats bolted from the top and what size they are? I am going to a jungled up junk yard Sunday to unbolt some seats for mine because they were missing from and someone bolted regal seats in it...its pretty shameful! I'm taking all kinds of tools as we always do when hitting the junk yards but want to make damn sure I at least have the original size and location, he won't let anyone get under cars on his property so hope and assume they bolt from the top. Also, anyone need anything on this car while I am there? It is all original only missing the radiator and grill.

Thanks folks

 

The seat bolts do enter from above. I can only go by memory but I think they are 5/16 course thread bolts with either 1/2 or 9/16 heads. I recommend taking WD-40 ... and maybe a torch if you can do so.

 

9/16 from the top

 

you guys are the best! Now i just have to actually get them and drag them out of there!