The striker's original one-month deal expired after Saturday's 1-0 win over Bradford and Glover is keen to keep the 27-year-old at Vale Park.
Gall has failed to score during his seven appearances for Vale, but his arrival at the club has coincided with an up-turn in form for the struggling Valiants.
"When you look at the record over our last seven games, we have won three and drawn one. Kevin has given us something different," Glover told the Sentinel.
"He has pace and can run at people and advance with the ball into the final third. It is just frustrating he hasn't scored because strikers do need goals. But he is a good pro."