Welcome to the forum, Samuel
.
You are right in that the dimensions of your sword are odd ... even critical.
It has surely been modified, probably salvaged from different origins. Apart from the bowl guard which, despite being also a small one, is not totally uncommon, all other sections, blade included, look like they would only fit a kid's hands.
Brass pommel and ferrules would also be mysterious components.
What is the grip made of, Samuel ... horn?