No worries,
Its a serial we have been looking into carefully as its getting close to the intersection of models. We may also learn a little from your mower also as it falls into a "until recently" unconfirmed and mostly unknown intersecton with victas next model,The model 5 special. Hopefully this proves to be an accurate example. Good luck and enjoy. A few members here at ODK have very concise info regarding the early victas, and are only to happy to assist. Also as stated date of man 57/58
.Just checked and it appears to be an early 58 possibly march or April if it.proves to be original.