Mallow, I think the answer is a maybe !
I had a relative in a similar position, and on his pre-WW1 service record it noted that in 1915 they had paid him back some of his "Buying out money" when he re-joined, however as he re-joined a different Regiment he had a different Service number and record, and as you may know 70% of these were destroyed in WW2, however we were able to obtain the Regiment War Diary which made reference to him, as he was mentioned in dispatches twice.
Good Luck
Wendi