Ok, sorry about the partial info
The model is a Spring Sound 1983. This was the only year they produced block logo variants.
The serial is correct for a maple neck version, and 5 digits suggest an ST50 (ST-60's will have 4 digits), and Rosewood variants will have an L prefix.
I have never seen a Springy with a black pickguard - your guitar is a replica of a 50's model, and they didn't have them in those days
An ST-55 (afaik) is an ST-50 with a custom colour, e.g. flamingo red or natural.
I think I can see from the pics that it has split tuners - old kluson-style. if you could provide a pic of the rear of the headstock I can confirm. Otherwise, the guitar will be an ST-40.
If you open it up, an ST-50 will have grey bottomed pickups with "U" stamped on them for this year. It will have a brass control plate
If it's an ST-40, it will have bar magnet pickups and it will be missing the brass plate and will have foil instead.
The neck is definitely '83. If you want to be sure the body matches, take a look at the codes in the body cavity and the neck heel (you need to take the neck off) the numbers XX=XX will (usually) match. If they don't match, the consensus is that the body and neck MAY be from two separate guitars. If they do match, it is 99.9% certain that the body and neck are from the same guitar.
Let's have some pics of the innards and the stamps and we can confirm.