I had not played in a Vintage Challenge for a while but the new restriction on MM got me excited to dust off some of my favorite 1-drops. I decided to start with Goblin Welder. I played the below deck to a 5-2 record.

3 Uba Mask
1 Myr Battlesphere
4 Goblin Welder
1 Lodestone Golem
4 Hollow One
1 Black Lotus
1 Mox Emerald
1 Mox Jet
1 Mox Pearl
1 Mox Ruby
1 Mox Sapphire
1 Sol Ring
2 Null Rod
3 Bazaar of Baghdad
1 Thorn of Amethyst
1 Crucible of Worlds
1 Mana Crypt
3 Tangle Wire
1 Trinisphere
4 Ancient Tomb
4 Mishra's Workshop
6 Mountain
1 Strip Mine
3 Wasteland
1 Tolarian Academy
1 Wurmcoil Engine
1 Sundering Titan
1 Pyroblast
1 Solemn Simulacrum
1 Mana Vault
1 Karn, the Great Creator
1 Mystic Forge
1 Mindslaver
1 Daretti, Scrap Savant
SB:
1 Crucible of Worlds
2 Ensnaring Bridge
1 Tormod's Crypt
4 Grafdigger's Cage
2 Witchbane Orb
1 Null Rod
1 Sundering Titan
1 Pithing Needle
2 By Force

Here are my thought:

I love the Uba Mask but I faced 3 other Bazaar decks in the challenge so it was boarded out a lot in this event.

Null Rod was great. I'd like to find room for 1 more

I sometimes struggled to have red mana. That's part of the reason I am light on red. I'd like to have another Pyroblast though.

Daretti was just ok. I won a gome because of him but he was underwhelming in general

I never got to use Mindslaver but I think it still has a place.

Wurmcoil was great against the BUG decks

Sundering Titan was the most frequent game winner. This guy is awesome.

I underestimated how often I would have Karn in play. I think that I should put Lattice in the board for the free wins.

I'm curious what you all are doing. What are your favorite things in Welder?

I've been having fun with this brew. I have not tried flash but I can see that finding a spot too.

4 Allosaurus Rider
2 Forest
4 Xantid Swarm
4 Tropical Island
3 Misty Rainforest
1 Scalding Tarn
4 Nourishing Shoal
3 Chancellor of the Tangle
1 Laboratory Maniac
4 Elvish Spirit Guide
4 Summoner's Pact
1 Mox Emerald
1 Mox Sapphire
3 Veil of Summer
1 Time Walk
1 Black Lotus
1 Ancestral Recall
3 Polluted Delta
2 Island
2 Autochthon Wurm
4 Neoform
2 Griselbrand
1 Force of Vigor
3 Eldritch Evolution
1 Mox Ruby

4 Ravenous Trap
2 Pithing Needle
2 Tormod's Crypt
2 Mindbreak Trap
2 Ceremonious Rejection
3 Force of Vigor

I look forward to every new episode of SMIP. It always makes for a great workday. Thank you for all you do.

I would play Cavern too. Mental Misstep isn't legal in Legacy.

I might try it in a black monty build to see if it is bad. Maybe like:

Main:
3 Sensei's Divining Top
1 Yawgmoth's Will
3 Grindstone
3 Painter's Servant
1 Demonic Tutor
2 Urborg, Tomb of Yawgmoth
3 Karn, the Great Creator
4 Leyline of the Void
1 Mana Vault
4 Mishra's Workshop
1 Voltaic Key
3 Thoughtseize
1 Tolarian Academy
4 Dark Ritual
2 Helm of Obedience
1 Black Lotus
1 Mana Crypt
1 Mox Emerald
1 Mox Jet
1 Mox Pearl
1 Mox Ruby
1 Mox Sapphire
1 Sol Ring
1 Necropotence
5 Swamp
1 Wasteland
1 Imperial Seal
1 Strip Mine
2 Polluted Delta
1 Time Vault
2 Scheming Symmetry
1 Vampiric Tutor
1 Demonic Consultation
SB:
1 Witchbane Orb
1 Crucible of Worlds
1 Ensnaring Bridge
1 Spellskite
1 Sorcerous Spyglass
2 Grafdigger's Cage
4 Shatter Assumptions
1 Grindstone
1 Helm of Obedience
1 Painter's Servant
1 Mycosynth Lattice

The thoughts that a proxy change would greatly increase Vintage's footprint are just as flawed as the thoughts that getting rid of the reserve list will cause vintage / legacy to become a premiere format. MTGO helped prove that this theory is false. MTGO proved that the price wall is not limiter as both Vintage and Legacy are, in general, less expensive to play than modern yet the participation levels for modern are exponentially higher. The gains of such a change end up being for a very small subset after the initial curiosity wears down.

As someone who plays every format, I say you hit the nail on the head by calling the set transformative. I think we are just starting to feel the effects of the set and it'll take a long time to fully land in Vintage. I sincerely believe that we may not be in Kansas anymore.

The Halloween thing is disappointing. I hate having to choose to skip Halloween with my family to attend this. I'd pay the extra for a better weekend

I might see how well it works in a 'Dark Times' type build with Crucible and Dark Depths parts.

I would do my best to make it too. I'm in Iowa City so it's not that far a trip for me.