Springboard was a 1970s reissue label... they released LPs by artists such as Sly Stone (Autumn period), Barry White etc from "before they were famous" to cash in on their current chart success.
Theres quite a few of these cash-ins on other labels as well - United (loads of Kent [60s] lps), Hallmark (Chi-Lites/Hi-Lites early releases), Post (Jerry Butler early solo stuff) etc.