That rear crossmember looks the same as mine which is '89 and is clearly the same as
@tottot 's '90 so I would say there is a very safe bet that it is the same as the original '86 your vin gives you. As
@Anaconda says the later style crossmember has captive nuts which like to break off when you tighten or loosen the bolts into it but I think these came in with the td5 and have the recessed rust trap hole next to them like the below, but it should be very easy to determine weather your holes are all the way through or if they are threaded.
View attachment 309224
I would also be carful of companies demanding a vin and then trying to give you the "correct" part with a vehicle that is not original. My '89 110 has a discovery 200tdi, and 300tdi wirirng looms throughout. I recently ordered an uprated hella alternator and the company cancelled my order because the reg I had put in on checkout was not suitable for that alternator. I had a very angry exchange detailing the modifications, quoting hella serial number rather than land rover part numbers, and stating it was the same alternator I had fitted prior to the fire and just wanted the same again. They reluctantly agreed to sell it to me on the provision I took full responsibility if it was the wrong part and did not fit. Unsurprisingly it fit first time with no mods as it was the same time I had fitted to my old engine.