Wander through the black forest and gather up a bunch of greydwarves and perhaps a troll and escort them to the dragur. While they are busy arguing over which group gets to kill you again grab your stuff and get out.

Grab it really fast and keep running, use dev commands to kill him, or have another player enter your world and kill it for you.

we gunna try to smash and grab because the dev tools idea makes my skin crawl

You could try to pull the mob away from the corpse. You come close enough till he notices you, then you hide behind a tree or break line of sight in some other way. The mob should start walking towards you pull him away and yeah.. pick up your tombstone.

Good on you for avoiding cheats.

Add details like available mats for armor and weapons. 2-star draugr are real ♥♥♥♥♥♥♥ to deal with, i freshly remember. I will say this every chance i get; Learn to roll.

How far into the swamps are you? Is there a chance to kite something to him or him to something?

Perhaps build a bench dig a pit and kite him there and knock him in.

Also, barring anything else, killing the Elder again isn't that bad an option.

update: got my stuff with a smash n grab

Grats on recovery!

Honestly, recovery stories are really the best part of this game.

The big guy had roved away from the tomb thank goodness, it was near a large stone tower structure

That stone tower is your new swamp base. There's almost definitely a spawner
inside. Destroy that of course and build a portal, bring in stone/cores and smelt
all the iron ore you're gonna find right there. Make a stonecutter first and
repair/finish/expand that tower. If you find enough iron you can upgrade your
forge (don't forget 6 copper) and fully upgrade whatever iron stuff you make.
A swamp base is also nice to farm leeches, entrails, chains and root monsters.

Next time just create highground/jump on the crypt roof and kill him using a bow. Very boring but very easy.

You could have also killed The Elder a second time and you would have gotten another key.

Spawners inside ruins are a good way to make a horrendous corpse run. If at all possible, by climbing up a tree or making a platform, it would be safer to snipe it with arrows. Remember that it can spawn archers who shoot right back at you. I'd say forget the tower and move on.