Storms in December 2013 wrecked the tree at Lydiard House in Swindon.
The gardening team at the council-owned estate saved the timber.
Now a local craftsman, Simon Webb, has created a series of pens which are being sold to raise money for the maintenance of the estate and parkland.
Lydiard income generation manager Ian Surtees said: "The new Lydiard walnut pens are beautiful and form part of our expanding limited edition product range we are developing to reflect the natural beauty and high quality of the Lydiard estate.
"The first Lydiard Walnut pen is an attractive heavyweight ballpoint pen featuring a hand-turned and finished body made from the 300-year-old walnut.
"Once turned and sanded, the wood then has 20 coats of clear acrylic applied and polished back to a dipped in glass finish.
"The acrylic finish not only enhances the beauty of the wood but also protects it.
"Finished in gun metal and platinum plating, the pen is presented in a high quality black velvet case and comes with a certificate of authentication and will retail at £75.
"While it is extremely sad to lose the tree, we are pleased to preserve the remaining valuable wood in this way.
The estate includes a Palladian-style house, church and a walled garden set in 100ha of parkland.