Saunders 4-blade masking attachment

[Fragomeni]

I have a Saunders 4-blade masking attachment that came with my Saunders/LPL 4550 XLG. Seems like a great tool and seems to work well with my glass 4x5 neg carrier but I’m a bit perplexed and can’t find any documentation for it. What’s confusing me is that it doesn’t mask down to 35mm. Does anyone know if this is by design and it’s just intended to be used with medium format and larger?

 

[Sirius Glass]

But you can figure out how to use it, right?

 

[Fragomeni]

But you can figure out how to use it, right?

Yes, I know how to use it (I assume - new to me enlarger and haven’t used it yet). It attaches in place of the standard stage. Glass carrier how’s above it and it seems very useful as I mentioned. Very easy to mask down to the neg size (all except 35mm in my observation) and eliminates needing multiple neg carriers of different sizes. I’m just confused why it masks down to almost 35mm but not quite.

Also, I disassembled it to make sure nothing was weird and I can see that the blades have an offset (if I take it apart again I’ll take a pic) so I’m wondering if the blades were maybe flipped at some point. I figured I would ask here before I start flipping the blades.