The Duchy, coached by former Plymouth boss Graham Dawe, have beaten Cheshire and Lancashire in the last two finals.
However, 23-times winners Lancashire did beat them at Twickenham in 2013 and 2014 and they also prevented Dawe winning three consecutive County Championship crowns with Devon in 2006.
Lancashire, coached by Dawe’s former Sale team-mate Mark Nelson, will include eight level three players in their matchday squad, which is double the amount Cornwall can call upon. But the Duchy are hoping their team can once again step up to the mark.
They have already Surrey 34-14, Devon 56-11 and Hertfordshire 45-28 to reach Twickenham for a fifth successive year.
“It has been an outstanding effort by a new team to get to the final,” said Dawe, who lost more than half of last season’s successful side for various reasons. “It has been a real 25-man effort to get the final.
“But now we’ve got to the final we want to give a good account of ourselves and try and get that win.
“The team has stepped up every week to the higher challenge and this weekend will, without doubt, be the biggest challenge yet.
“Lancashire are a physical, hard-working side will proven experienced players. They have got a pretty varied game with a lot of hard runners.
“However, the one thing that has stood out about this Cornwall team this year is that they have not let disappointment get in the way of the way they do things. If the opposition has scored they have gone right back at them.”
Cornwall do include four Plymouth Albion players in their squad. Robin Wedlake and Matt Shepherd will start, while Seti Raumakita and Dan Collier are named among the replacements.
Also in the Duchy’s side are former Albion players Jake Murphy, who is captain, and Sam Matavesi, who will form a back-row with Penryn players George Jones and Grant Randlesome. Jones and Randlesome have been playing in the Cornwall/Devon League this season.
As well as having a new squad this year, Cornwall have also had a new backroom team with Rhodri McAtee, Marek Churcher and Tristan Lark, who have all had spells at Albion, coming into the set-up.
“I’m really pleased with the contributions of Tristain Lark, Marek Churcher and Rhodri McAtee in helping to prepare the team,” added Dawe.
Cornwall: Matt Shepherd (Plymouth Albion), Lewis Vinnicombe (Redruth), Robin Wedlake (Plymouth Albion), Jake Murphy (capt, Barnstaple), Tom Notman (Redruth), Joe Elderkin (Redruth), Jack Oulton (Redruth), Tommy Phillips (Redruth), Richard Brown (Redruth), Craig Williams (Redruth), Tony Whittle (Camborne), Bryn Jenkins (Barnstaple), George Jones (Penryn), Sam Matavesi (Camborne), Grant Randlesome (Penryn). Reps: Matt Ballard (Wadebridge), Dan Collier (Plymouth Albion), BJ Chapman (Redruth), Andrius Zacharovas (Camborne), Chris Fuca (Redruth), Seti Raumakita (Plymouth Albion), David Mankee (Camborne).