2.5TD radiator oil pipe adaptors

Hi everyone. I've just got a new radiator (part NTC6168) for my '89 110 2.5TD (19J), but when I've taken the oil pipe adaptors out of the old rad and tried to fit them into the new one, they don't fit 'cos the threads are different. Has anyone had this before?! I've checked with the suppliers (a reputable firm), and several others, as well as the Defender parts catalogue, and I've definitely got the right radiator. The oil pipes look like the originals. The supplier has said that you can get the adaptors (NTC3858), but at roughly £20 each I don't fancy buying them, and finding they fit the rad but don't fit the oil pipe!! I've got some precious spare time this weekend and Monday, and was hoping to get the new rad fitted since it's near the end of the long list of stuff that needed sorting!! Does anyone know the correct size and thread of each side of the adaptor? Any help/info that you all have would be greatly appreciated. Cheers.

I know my 200tdi rad was 1/2" BSP and I read somewhere people swap the fittings over when converting to tdi

Thanks for the info Mark. I think I'll just bite the bullet and buy two adaptors and see if they fit both the rad and the pipes.

You might find more info if you search for 200tdi conversion oil cooler pipes it's comes up quite a bit and there is a couple of different types