Prior to being put on display , the locomotive 's original tender was switched with another NKP steam engine # 639 .
The tender on 639 was in need of repair and 587 's original tender was in good mechanical condition .
Prior to being put on display , the locomotive 's original tender was switched with another NKP steam engine # 639 , because the tender on 639 was in need of repair and 587 's original tender was in good mechanical condition .