Must say I fancy one of those paraffin burners for the T25. Are they still available? I couldn't find any retailers from a quick google search.
Depends what you mean by "paraffin" burner.
The Trangia burner for paraffin (ie the one that Trangia sell) is a multi-fuel burner, originally made by Optimus and now by Primus.
Googling "trangia multi fuel" brought up lots of hits. In the UK all the hits suggested they were still selling the older optimus model, which is an excellent burner, but the new Primus burner will also run on resealable gas canisters. Trangia do not recommend running the liquid fuel burners in the Trangia 27 because of the amount if heat they produce and the risk of damaging the aluminium.
But you can buy a Primus Omnifuel or Optimus Nova (and others), remove the legs and using a cheap adaptor (£7.00 or there abouts
http://www.base-camp.co.uk/Optimus.html part 9101) fit the burner into the Trangia.
The more famous conversion is probably the kap arctic (no longer available) using the burner from an Optimus 111 stove, but adaptors are available to "roll your own" See
http://kotisivu.dnainternet.net/luontola/ultimate/index_eng.htm for some details.
But you need a burner form a second hand Optimus 111, plus the fuel pump and fuel hose from a modern Optimus Nova or Primus Omnifuel, plus the adaptors available from the link to put it all together.
With the exception of the official Trangia multifuel burners, most of the conversions need you to make an extra hole in the Trangia to allow access to both the fuel hose and the fuel control knobs.
I have both a Optimus 111t and primus Omnifuel burners adapted to run in a Trangia 25 and the combination is tremendous. Heat build up is scary, and the wind shielding together with the heat retention makes priming the liquid fuel stoves much easier than when relying on conventional wrap round windshields.
The big advantage of the 111t option is that uses a silent burner , which is a lot more pleasant than the roar of the modern Multifuel stoves. Unless you fit a Berniedawg silent burner, but demand rather outstrips supply for these
http://home.comcast.net/~bigdog660/Bluewater_Stove_Restoration/Main_Page.html
Graham