Espresso grinder tech support request

I have a rather impressive collection of thrifted equipment I use for my morning latte. Each piece has required a little bit of investigative repair in order to get it working just right, but I've recently been stumped by my newest addition, a Bodum conical burr grinder.

My current espresso machine is a single boiler Breville with a standard portafilter (no diaphragm or valves in the portafilter, so the resistance needs to come from finely enough ground coffee.)

My question is this; is it possible to calibrate the Bodum grinder at all? It's finest setting is apparently not quite fine enough to provide the right resistance for the espresso maker, so I've needed to regrind my coffee with a blade grinder to get the right consistency.

Cheers in advance!