??,
You will see below that I have a few family names in Bisley. I've seached every year from 1608 using the LDS film of Bishop's transcripts (I've hired it three times - found new names!) and I can assure you that the LDS extractions from the film I too used, are very accurate in their present contents providing they are readable and on the film because I found that some years are missing.
I say, "present contents" because if an LDS member found a family name in the BT's and submitted it i.a.w. LDS procedures, the batch entry will now have been deleted and will appear as a submitted entry. That does not mean that all submitted entries in the IGI were once in an extracted batch - far from it

As there are 651 Dark baptism entries for GLS in the IGI (submitted + extracted) and only three of those are from Bisley and are extractions, you will find no other help unless somebody can search the Parish Register in the Gloster R.O. but that's asking a lot.
You could always hire and search LDS film 417124 but it will not help more than the IGI and there's no LDS film of Bisley PR's - more's the pity for I would have hired it.

Regards
Chas