Property inherited with income rights restricted

My client, husband and wife, recently inherited 4 let properties from the husbands late uncle

A deed of variation was exercised so the income from these let properties is paid to the widow for the reminder of her life, net of any taxes and expenses

My question is, who is assessable on the rental income?

I suspect what has happened is the property is now held in trust, being a type of Immediate Post Death Interest trust.  So for IHT the property will form part of the widows estate as Settled Property coming to my clients as remainder men on her death (and should have therefore been an exempt legacy to spouse in the deceased's estate - I do not know if this was the case).  The income will be assessed on the husband and wife as trustees at basic rate producing an R185.  On the widows death, the assets will receive an uplift to the then current market value for CGT.  Would anyone agree this view is correct?  

If this is the case, would you agree I could suggest the income continues to be paid directly to the widow to avoid the requirement to complete a trust Self Assessment Tax Return. Then as the income is not received by the trustees (i.e. my clients) they cannot then be assessed on it as trustees thus eliminating the requirement to complete a trustees tax return.

There is not a trust deed - unless the Will and DOV could be regarded as such?

Or ... am I overcomplicating the position and the income should simply be assessed on my clients personally who will then pay the rents after expenses and tax to the widow as well as them already owning the property for IHT and CGT.

Thanking you in advance for any responses

Ben