Well this all makes a lot more sense. The information I was using was direct from my wife who doesn't really take much interest in these things. She has finally managed to get her login details reset so I've been able to see the real information.
What she thought was the final salary scheme conversion to a DC pension pot is not the case. The final salary scheme was converted into a CARE scheme so DB NOT DC.
This explains why the lump sum paid to her estate in the event of death is so small.
What I've done in any case is to take the transfer value and looked at annuities. Her DB annual pension goes up by RPI up to a max of 5% p.a.
Looking at comparison sites for lifetime annuity rates with a 3% uplift the going rate seems to be about £3,900 per £100,000 or purchase - this would give her an annuity about 25% below the DB scheme prediction. So quite a hit.
In the event of death before 75 a cash sum of 5 years of pension would be made. In the event of death before 75 I would receive half the pension that would be payable to her.
So in conclusion it looks like we would be far better off sticking, rather than taking a transfer value which is much smaller than would be required to match the benefits.