There also is - or was, as the project seems to have gone dark - a 64-bit branch of
FreeDOS, which would have
exactly been a 64-bit recreation of MS-DOS.
There are some here following
a similar trajectory, such as
~ (Tilde), though there are even more, such a
tay10r (and
IanSeyler, the originator of BareMetal, who posts here from time to time), are working on similarly
low-abstraction systems that don't specifically emulate MS-DOS.
However, the existence of existing or earlier projects should not, and presumably will not, stop you from going it your own if you choose.
It is common enough that it is even one of the wiki's
developer archetypes, the one called
Lino Commando. While the purpose of the archetypes is to poke fun at different sorts of devs, as well as point out the pitfalls of different approaches, most of them aren't
bad things - they are just approaches we've seen frequently. Most of them were even created by someone they describe (for example, I created
Alta Lang, which is a good description of my own approach).
(The exceptions are
Duct von Tape and
Bossy Boots, which are
always anti-patterns to be avoided. I have no reason to think that either of these apply to you - so far - and this warning may help you avoid them if you were inclined towards one of them.)
Anyway, this should give you some idea of what other projects exist in this vein already, so if you are looking for either an existing project to join, or advice on who to proceed with your own, those are some of the ones to talk to.