Declaration of Trust?

My client’s mother in law signed a Declaration of Trust to hold the beneficial title of her property for her son in law (my client) and grandson equally.

Nobody can find the Declaration of Trust although there are official letters confirming it was completed.

No-one can remember/knows if the equitable title is held as to tenants in common or joint tenants.

I have been tasked to make my client’s Will while the firm who dealt with the Dec of Trust search it out…

My client would wish to hold as Tenants in common as he wishes to leave his share into a life interest will trust for his wife’s benefit after his death.

He would also like his wife to have a half share of his ‘half share’.

I have drafted a Notice of Severance for my client and son in law to sign in the interim period- incase they are joint tenants in equity- any issues here?

I was also thinking of doing a Declaration of Trust for my client to sign stating that he holds half of his share of the beneficial title for his wife (and she can then include a share of that property in her Will, also going into life interest trust).

The legal owners will be my client and son in law in due course, when the Dec of Trust is finally located. Until then, can I amend a ‘usual’ Dec of Trust deleting reference to legal owner so my client declares himself as a beneficial owner only, wishing to hold half of his share on trust for wife?

And I also believe this would need to a registered on the Trust Register !?

Thank you.