I'd file a flat on the axle where it sits in the dropout.
I would just do this tbh, if you buy an axle kit it's just a regular axle with flats put on a it more professionally.
And I don't know about Gran Compe but DA hubs just have a spacer for 120/no spacer for 110, if an 110 conversion kit for the rear exists they should be the same so you can change the spacing yourself. Otherwise you will be able to fit it in there it'll just be a little annoying when you take the wheel in and out...
I would just do this tbh, if you buy an axle kit it's just a regular axle with flats put on a it more professionally.
And I don't know about Gran Compe but DA hubs just have a
spacer for 120/no spacer for 110, if an 110 conversion kit for the rear exists they should be the same so you can change the spacing yourself. Otherwise you will be able to fit it in there it'll just be a little annoying when you take the wheel in and out...