How to proceed?

GaleSF63

RAS said:

If he married in the UK, then they can get his marriage certificate.  Research your family history using the General Register Office - GOV.UK (www.gov.uk) which will detail his wife's name (assuming England or Wales, Scotland is easier).

With that date English and Welsh marriages will also be on Ancestry and possibly BMD or findmypast, so may be worth getting a free fortnight's subscription some time if it's not on free BMD?

I'd also suggest that they box up all paperwork and go through it at a later date looking for everything that might be a certificate or is in a foreign language. And look for any old passports or overseas residence permits.

Until they have a clue about which country she came from, it's hard to suggest more.

Ancestry may be available at a public library. 

Marcon

There's been no mention of the 'third' possibility: that the pair were judicially separated rather than divorced. If that's the case, even though they are still technically married, the estate of the deceased is treated as those their spouse had already died, so she wouldn't inherit under the rules of intestacy.

Sea_Shell

Marcon said:

There's been no mention of the 'third' possibility: that the pair were judicially separated rather than divorced. If that's the case, even though they are still technically married, the estate of the deceased is treated as those their spouse had already died, so she wouldn't inherit under the rules of intestacy.

How would one check this?

Qust323

I’ll let them know the third option but could you tell me how they would find out please? Also if they find out she wouldn’t inherit do they still have to split the parent’s estate into 3 or can they split it into two as they would inherit his estate? 

YBR

My strategy would be to divide it into 3. The 2 sibling shares can be distributed when the parent's estate is ready to do so, with the third share going into the brother's estate. 
This means there are definitely funds in in the brother's estate to pay for searches and/or solicitor fees. If and when it's established that the siblings are the heirs the remainder of that estate can be paid out.

Keep_pedalling

YBR said:

My strategy would be to divide it into 3. The 2 sibling shares can be distributed when the parent's estate is ready to do so, with the third share going into the brother's estate. 
This means there are definitely funds in in the brother's estate to pay for searches and/or solicitor fees. If and when it's established that the siblings are the heirs the remainder of that estate can be paid out.

That would seem a good plan. Set up an executors account for the brother’s estate and transfer his share of the estate into that. I would certainly employ a company that specialises in tracing people if you can’t find the relative paperwork in his personal effects.