Help! Any info will be greatly appreciated

[Vanalog]

Just acquired this lens for a view camera I recently purchased, can't find any info on the lens such as focal length, if it's convertable and too what. Any info or tips you have will be greatly appreciated.

[lucaas]

The lens is an 8 elements/2 groups symmetrical design, so it can be used as a convertible lens. When using both groups, its focus length is 6 1/4in and aperture is f6.8.
When using rear lens only, the aperture is a f13.5 and the focus length is nearly twice of the lens when using both lenses.

[Vanalog]

Thanks! Sorry I'm new to the large format game, would that mean it's equivalent to a 155mm lens? And when front element removed it's around 300? Also any idea on the aperture numbers there's some in white, then some above that look hand engraved. I was thinking the original white was a older scale and someone engraved the above marks in fstops.

[goamules]

Use: http://www.convertunits.com/from/inch/to/mm

You have the lens, or will soon right? Simply remove the front element and measure the focal length (from lens to ground glass, focusing on a distant tree).

Hand engraved marks? You'd have to ask who engraved them.