that would be minimal effort compared to everything else.
abaco is much more functional and stable than the (actual) links port never was, we used it for a while, but abaco has completely replaced links now. The binary is much smaller too and it supports https with factotum, uses webfs, etc.
I think it only really needs CSS and javascript to be functional enough (and plugins, but that is another matter).
Any browser anyone writes/ports needs javascript and that is (mostly) independant of anything else and needed, so putting some
effort there is probably good whatever the path taken. Spidermonkey javascript implementation is in C and highly doable though very very boring.
With that, CSS and some small work (like chaging the fonts for input forms)
abaco could be made into a simple, powerful well integrated (pre html 5, but that is another different level of complexity) browser for Plan 9. This are my two cents, but I don't have time for that and probably won't, so IŽll shut up now :-).