Here probably is the answer (or more questions!):
<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->The Vikrama era begins in 58 BC. We know this because a very late text, Meratunga's Theravali gives a story of how King Vikramaditya expelled the Sakas from Ujjain and established the era, and gives a formula for calculating the Vikrama era from the Saka (Majumdar, 1951). The term Vikrama is fairly late, and was not the original appellation of the era. Before the ninth century the Vikrama era was known as the Malwa era. This Malwa era can be traced to a group of inscriptions of the fifth century, found to the south of Mathura in Rajasthan. These inscriptions include the word 'Krita' and this allows them to be linked to a group of inscriptions dated 295, 284, 282 (ie the first half of the third century) from the same region. This is where the trail stops. These are the oldest inscriptions known with certainty to be dated in the era of 58 BC.
http://www.kushan.org/essays/chronology/azesvikrama.htm<!--QuoteEnd--><!--QuoteEEnd-->
<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->There is a simple rule of thumb in epigraphy (and source criticism in general) that <span style='color:red'>if everyone agrees on what an inscription says then nobody really cares</span><!--QuoteEnd--><!--QuoteEEnd-->
<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->The Vikrama era begins in 58 BC. We know this because a very late text, Meratunga's Theravali gives a story of how King Vikramaditya expelled the Sakas from Ujjain and established the era, and gives a formula for calculating the Vikrama era from the Saka (Majumdar, 1951). The term Vikrama is fairly late, and was not the original appellation of the era. Before the ninth century the Vikrama era was known as the Malwa era. This Malwa era can be traced to a group of inscriptions of the fifth century, found to the south of Mathura in Rajasthan. These inscriptions include the word 'Krita' and this allows them to be linked to a group of inscriptions dated 295, 284, 282 (ie the first half of the third century) from the same region. This is where the trail stops. These are the oldest inscriptions known with certainty to be dated in the era of 58 BC.
http://www.kushan.org/essays/chronology/azesvikrama.htm<!--QuoteEnd--><!--QuoteEEnd-->
<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->There is a simple rule of thumb in epigraphy (and source criticism in general) that <span style='color:red'>if everyone agrees on what an inscription says then nobody really cares</span><!--QuoteEnd--><!--QuoteEEnd-->