Neutrik NC3FP-B-1 is the smallest available 3-pin female XLR panel mount connector.
It is not in the shape of the now-industry-standard unified D size, meaning this connector won't fit into the vast majority of pre-punched panels available.
However, if you're repairing an older piece of equipment - you'll find these connectors on a variety of lecterns and power amplifers - then, you've come to the right place.
3 pole female receptacle, solder contacts, black metal housing, gold contacts
Smallest available traditional style metal panel mount connector with large solder cups for easy hard wiring.