If no luck, you can try adding to the width of a tyre that's in situ by cutting an old/wide inner tube or other material you can wrap around the tyre and just tape around it to follow the shape of the tyre, that way you can build up the layers to reach the 32mm width in one section to see what the clearance is.
Something like pipe lagging foam might also work to bulk out an existing tyre.
If no luck, you can try adding to the width of a tyre that's in situ by cutting an old/wide inner tube or other material you can wrap around the tyre and just tape around it to follow the shape of the tyre, that way you can build up the layers to reach the 32mm width in one section to see what the clearance is.
Something like pipe lagging foam might also work to bulk out an existing tyre.