Foundry in 75mins is pretty fast (normal pugs finish 1st quest in the same amount of time), using the Wiki build(War, 3monks, 2-3eles or 2e + ss and a bip).
However, i did some farming as 600hp spirit bonder tank(monk/mesmer) using 3 heros(smiter/prot, smiter/heal and a ranger/spirits), and i can finish first quest in less then 30mins.
I havent been able to finish 2nd quest(using 4-man build) yet, but im pretty sure the team you heard of used a similar build.
Here it goes:
Tank: Monk/Mesmer (Blessed Aura, Essence Bond, Prot Spirit, Spirit Bond, Shield of Absorption, Spell Breaker, Sympathetic and Ancestors Visage)
Attributes: 14 Divine Favor, 14 Protection Prayers and rest in Illusoin Magic.(you might wanna replace the SV/AV with Mantra of Resolve and Channeling, Inspiration Magic, and let the SS bring AV/SV)
Smiter/Prot: Monk/Any (Holy Wrath, Retribution, Vital Blessing, Life Attunement, Rage Signet, Signet of Judgement, Bane Signet and Rebirth)
Attributes: 16 Smiting Prayers and 15 Protection Prayers.
Smiter/Heal: Monk/Any (Mending, Watchful Spirit, Succor, Balthazars Spirit, Rage Signet, Signet of Judgement, Bane Signet and Rebirth)
Attributes: 16 Smiting Prayers and 13 Healing Prayers.
Ranger/Spirits: Ranger/Monk (Troll Unguent, Serpents Quickness, Quickening Zephyr, Edge of Extinction, Brambles, Famine, Essence Bond and Rebirth)
Attributes: 16 Wilderness Survival, 15 Beast Mastery, 6 Expertise.
By adding 2 SF eles, SS and Bip, im pretty sure u can finish Foundry in about 1 Hour+.
Its also possible to save alot of time on last part by avoiding most of the patrols and tank the Fury by the gate to Veil(far south of Foundry)
If you feel like making a team for this(or have any questions about the build/strategy) just PM me in game.
My IGN`s are Hansiac Hellblade(war), J A M A I L(monk) and Justin Priest(necro)
A screenshot of me and my heros after completed the first quest:
) I heard a team how made all the foundry in 75 minutes... 
