The LGW working arrangements and contracts originated in the Dan-Air take over but the equipment and those contracts etc now are very different. Essentially everyone at LGW is paid the same as their LHR counterparts, but with different, lower pay caps. Rostering is different there being no Bidline at LGW. IF the new rostering system adopted at LHR turns out to be Bid Trip then it is highly likely that this would also be brought into LGW, bringing the T&Cs at the two bases closer together, though the pay caps would still be lower at LGW.
As the change of fleets at LGW continues there willl be some "Schedule K" work at LGW - essentially LHR pilots operating at LGW but on constructed Bidline trips at LGW, this includes hotac at LGW as dual basing is not allowed. All 777 work at LGW is done by LHR based pilots under Bidline, there is no 777 base for pilots at LGW nor is there any intent for that to change.