American disability benefit - disregard or not? 

Hi

We have a pensioner who receives dla abut also received a payments from US Government – Disability Insurance Benefits (started 1994.) which morphed into Retirement insurance Benefits when he reached US pension age in 2003. ( he was in the US Navy for a while)

We have treated it as income and he doesnt get full HB

Im happy that if its the equivalent of a war pension, then it can come under sch 5 para 1 and 2 and have a disregard
But he says its the american version of PIP/AA – and it should be disregarded in the same way – I cant see anything in sch 5 which would allow us to disregard it – anyone any idea whether it should be disregarded or not?

UPDATE _ i trhink i was looking in the wrong p[lace - reg 29 says what is income and says PIP/DLA (and a long list of other incomes are NOT treated as income then para K says ” all foreign social security benefits which are similar to the social security benefits prescribed above” which I am reading as any foreigh equivalent benefits should be diosregarded as income - so I think we should be disregarding it?  Does that sound about right? ( i really want to disregard it!)