I would love to put together a 7.62x39 Enfield, looks like fun and I always love iron sight service rifles.
I know that there were rifles offered in the past, but it looks like they are long gone.

Do you guys know if anyone offers a conversion kit or what would be involved in converting one?

Some porn:

I think that second picture was from the Aussie company that was making them back in the day.  I haven't done much in the way of research on them, but wasn't the x39 a full re-barrel deal, where a x54 was a chamber ream-job?  I'd think that a big problem right now would be finding donor rifles... twenty years ago when #1s were a dime a dozen (or more like $85 bucks a grenade rifle), but now?

if one had a grungy rifle/action laying around the economics change a bit but not by a lot. Otherwise what is the cost to aquire said grungy rifle or striped action and the work and time to convert to x39 vs the equivalent dollars for .303 ammo is probably not favorable to a conversion

I agree with you on the economy of the whole thing... but at the same time, I really don't think this is something you do because you're looking to save money.  You do it because it'd be freaking COOL.  Long time back I really wanted to figure out how to do the x54 conversion just because I liked the round more than .303, sure wish I'd grabbed a few of those grenade rifles way back when.  Oh well, hindsight 20/20 blah blah, right?

You could grab a few No4 receivers to work with -

https://www.brpguns.com/231002-lb4-four-long-branch-1944-no4-mki-receivers-ffl-required/?utm_source=bayengage&utm_medium=campaign-email&utm_campaign=copy-of-just-in-10-3-23

Well that's interesting!

Other parts can be found at SARCO, Numrich, Liberty Tree, Apex, etc.  Millions made and lots of parts - Tommy-issue forends and some handguards are a little tough to find.

Australian International Arms made a few hundred x39 and a few hundred 308 new-manufacture SMLEs back 20+ years ago or so. As I understand it, the 308s went to Canada and the x39s went to the US. I spent years looking for a x39 and finally found one a decade or so back. They nominally feed from AK mags, but in practice I found it almost totally unwilling to work with anything but the factory 10rd mag.

Accuracy was..interesting. Seems they used .308 spec barrels rather than .311, and that led to wildly varying results. I threw a Leopold Mk4 on mine and found some steel cased loads that were right at 1 MOA for 5 rd 100 yd groups...and other loads (including good brass cased US ammo) that were 10-12 MOA.

Who the hell knows what you'd pay for one if you found it now...$1500 maybe more. I'd expect the search to take years, and you'd need to be willing to pay any asking price without hesitation, because there's just aren't many around.

I have a 2A in 7.62x51.  I put a chamber insert to reduce it to 7.62x39.  It feeds just like it was made for it.  The orignal chamber is "roomy" so it may not work in your 2A.   YMMV.