nearly all my Night Flying models are built from Various size Clear Polyethylene Mailing tubes.
I get mine from McMaster-Carr but I'm sure the same sizes are available from just about any Packaging/shipping store.
Most are not exact match sizes to our Standard paper body tubes but close enough that a little tweeking makes them work great.
Check out the McMaster Catalog #2044T41,42,43,44,46,48,49,51 & T52.
2044T52 is the largest available 2.55"ID with a .028" wall give an OD of 2.606" As nearly a perfect match for 2.6" BT-80s as your gonna find. All come in 48" long sections as well.
There are also some colored T8 and T12 Lamp covers that work pretty well for BT-60 body models. don't have the cat. numbers handy but the come in amber,yellow red and green
Heres a couple examples. I unfortunately won't be making Naram-51, but the Phantom NITE Nike-Apache will be there, Hopefully to be flown by the NIGHT Launch RSO.