The phrase "a sort of prototype" is correct and usable in written English.
It can be used when describing something that serves as a preliminary model or example of a concept or product.
Example: "The initial design was a sort of prototype that helped us refine our final product."
Alternatives: "a kind of prototype" or "a type of prototype".
Lutchman, a little man, is a sort of prototype of and antithesis to Biswas, to modernism's "little man".
Looking back at them now, tThey seem delightfully retro: a sort of prototype computer game constructed out of the only materials available at the time.
In 1972, Dick Taverne, a former Labour minister, resigned from the party after a bitter dispute with leftwing Labour activists in his constituency, and the following year set up a sort of prototype SDP, the Campaign for Social Democracy.
They are a sort of prototype for a band that outpunked even the very idea of punk by giving impossibly little of a shit about what may have been expected of them.
Antony Gormley's Iron: Man – a sort of wonky prototype for The Angel of The North – perfectly expresses the culture of Brum.
He suggests in a paper published online this month in Trends in Cell Biology that scientists could use dance for a sort of rapid prototyping of hypotheses bodystorming rather than brainstorming.
The original Xbox One looked like a sort of mid-70s prototype VHS video recorder – all bulk and black plastic.
I had remembered it as a laddish, banter vehicle prototype, a sort of Top Gear for laptops and Xbox games.
You act as a sort of live mannequin, trying on prototypes and getting paid upwards of $250 an hour.
A 360-degree laser scanner captured precise three-dimensional measurements of the real Mr. Schwarzenegger and then translated the data into a model of the character made by a rapid prototyping machine, a sort of printer that cranks out 3-D physical objects rather than simply documents.
