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953 is 85 pages. 9293 is also 85 pages (with 13 pages of appendix), although they switched to a proportional font for the PDF so there's probably more text.
Of course you would make an HTTP/2 server, if you were looking for active push support and the like.
I can write you an HTTP/1 server in bash in an hour or two.
I assumed rfc793 was shorter than 9293; false. 9293 is significantly shorter.
9293 also has a lot of implementation notes from the past.. many years of folks that have done this.
So yeah, 9293. Seems like a solid rec.