Western Electric 317 battery dilemma

[notoiphones]

Purchased a WE 317P wood wall telephone. It came without any wiring or other internal parts but does have a working magneto.
It is now rewired and contain all the necessary parts.
The wiring diagram indicates three (3) WE Blue Bell batteries in series all in a nice, tidy row.
The photographs I find only show two batteries in a 317P (& many other 317 models).
The box will hold 3 standard No. 6 batteries, but they must be staggered to get them all in.
How many & what type batteries should be used in this? Is it 3 volts or 4.5 volts total in series?
Thanks

[dsk]

As far as I got it it was used with 3 or 4.5V batteries depending on the need. (line quality/length)  If it works OK with 3V it is OK with 2 batteries.  They were good at practical solutions those days   and not so good at following standards.

[notoiphones]

Thanks for your reply. For the sake of adequate power I am going to use the 3 battery configuration as shown in illustration.
Thank you again!

[dsk]

Looks great!🙂

[HarrySmith]

What are the batteries you used? Are those repro labels?