Iranian T-54? -B or -3?

Where did Iran get the hulls used when upgrading “something” to the Safir-74 configuration?

" Crucially, with the advent of the Iran-Iraq war, the West and East seemed to take sides, and while Saddam’s regime was backed by Westerners (but received equipment from USSR and China also), traditional Iranian defiance towards USSR declined but still made China, now antagonized towards USSR a natural provider. 480 T-72, 75 T-62, and 540 T-54/T-55/Type 59 were obtained. In addition, North Korea, but also Brazil became short-term military providers. These were accompanied with technological transfers, laying the foundations for future local armament industries."

They did not have them at the beginning of the Iran-Iraq war in September 1980 but when did the deliveries