original master recordings means it uses the first master and 180 gram and all the fancy stuff
if it just says mobile fidelity sound labs it probably is a lower weight (specifically if its a grey stripe). and they didn't use the original master but some other tape or digital
@JonnyH also a note that it seems that mofi only does this with the silver/grey label.. if the color more matches the album art like an OMR... its probably still 180 gram...
no matter what it will be mastered by the mofi team
Current MoFi Original Masters are 180 gram. Previously they were 200 gram, and the early ones were 140 gram pressed on translucent JVC Super Vinyl- my favorite.
if it just says mobile fidelity sound labs it probably is a lower weight (specifically if its a grey stripe). and they didn't use the original master but some other tape or digital