8 photos showed up .
Keep the OEM filter cage . You can get a Unifilter for a DT1, which is the same unit fitted to RT1's .
The unifilter comes with it's own cage , but it is a bit too long ( 8-10mm ) .
Change the cage over , with the Unifilter element on the OEM cage , and you're good to go .

Yes, your pics are visible. 

It worked for me. I see all 8 photos.

Edit
oops. I didn’t see pahiker already replied.

I see 8 air cleaner photos with an expiration date in November. 

Thanks everyone. Good to know it worked eventually

Swoop thanks for the filter info though I guess that is in the USA? If so shipping costs are crippling. I will investigate later today. There is a genuine filter on eBay but it is over £60

Markt the expiry date automatically set and I couldn’t see how to change it. Will try again next time. And there will be plenty of next times I am certain.

Anyway the filter housing looks fine. Just needs a clean and paint with something silver

I may start a project thread as I have so much wrong or missing on this bike.

Finally don’t judge any fasteners, cable routing etc at this stage as all I am doing is trying To do at this stage is assemble most of a bike then will take apart and paint, assemble smarter and try to end up with a useable bike that looks period.

Thanks again for the feedback an to gr8uncleal for his coaching and guidance here in the uk

Until next time……

Hi Ian, I see pics of an airbox when I clicked on the link. Nothing else.

Sorry, late to the party.... didn't see that there was a Page 3!

Thanks phyllo.  It’s all I wanted you to see and I imagine all you would want to see!  Cheers

I noticed that you said you are planning to paint the airbox silver. Obviously, your call, but I believe this part would have been black when new.

Really?  I haven’t seen a black one before but not saying you are not correct. I am learning every day. 

I will investigate but most pictures I have seen show ‘metal” type effect of either silver paint or galvanised type finish. 

Interested to find out. It’s just as easy to paint any colour. I may as well get it right.

thanks for taking the time to reply.