Hi,
I'm not sure if the the two types of trigger guard are directly interchangeable and may have been replaced with the alternative guard at some time.
We certainly know that the existing grips from Frank Clarke' final Titan design were used up on the Warrior. You can also see the clear visual likeness that the 7th series Titan had to the first Webley Mk1. Frank Clarke had a recognised influence on the final Webley product and I believe received royalties in recognition of his contribution.
Regards
Brian