They did not carry many pax anyway Graham.I just put the FR Lanc pic up as a laugh (it is a lovely pic though)
I honestly think that the CofG was not a serious issue as rgds the Lancaster,the Lancaster had tremendous lifting capabilities and a few hundred pounds of ballast (if reqd) would make little difference – if I may quote myself from this thread almost 10 years ago….

I doubt the CofG would have been a serious problem,if there was a real necessity to improve the performance of the a/c !!
The removal would have made more space in the nose compartment and a less ‘draggy’ nose could have been fitted.
Large a/c usually have ballast weights fitted anyway,so a few more would make little difference if necessary.
In the mid 70’s we had a Canberra B2 return from a major service…we had trouble getting the elevator trim correct (a/c should have run out of nose down trim at 400-450 kts on test flight,but was 110 kts out).
We eventually found that the major servicing unit had ‘forgotten’ to refit the ballast weights in the nose 😀 (big lead weights),the C of G must have been way out but she still flew ok.