Help with court case please

[1amber]

Hi all I'm hoping that someone can help with this. My son went into partnership with a friend & opened a restaurant. He became a guarantor for some fridges. The partnership broke down & he signed over his shares on the understanding that he was removed from all legal & financial obligations which was agreed. The restaurant closed 6 months later & the x-partner sold the fixtures & fittings onto a new owner. He did not use the money to pay off the fridges & now my son has had a court summons for nonpayment of the monthly repayments. My question is, legally does my son still own these fridges & can go and get them as he is the guarantor? Was it legal for the partner to sell them in the first place if he did not pay off the remaining lease payments? Can my son dispute this claim. Many thanks