8dayweek
Sorry I was off pretending to be a grown up but I see jake has already given you the gov link re the fraud figures so I don't have to find it myself.
What your talking about regarding historical claims....
The extra need benefit that is now called DLA/PIP before the early 70's was just called mobility allowence and was only paid afaik for mobility related disabilities and attendance allowence was for care needs (but introduced a few years before mobility)
Supplementary benefits were prior to IS was weirdly called supplementary benefit amd if you were to sick to work was invalidity benefit two types one contribution based or previous employment based the other none contribution based but this was deamed to be so discriminatory against women that in the late 70's changed to sever disablement allowence.
They also had benefits (and still do in some format as your aware) designed to compensate for disability things like war disability pensions.
Prior to about 1971 people who couldn't work due to disability had no additional support and were treated much the same as people who just didnt work.
When mobility allowence and attendance started going life time awards were rare unless it was rather obvious you wouldn't get better and in about 92 they started reforming them. Under 65's with life time awards were reassessed and many switched over to annual renewal DLA or 3/5/8 year renewals but those who were assessed as needing lifetime awards were often left on MA/AA with a long term staggered automatic change over.
It would have been highly unlikely for someone with a bad back likely to mend to have been able to first be awarded the circa 70's version and even more unlikely to retain it during the changes.
However I will agree that its a high possibility with the old means tested supplementary ones.