vbates

I need some information on the furnace that we have in our home at this time...Its a Williamson Tempomatic Natural gas model# 1114-12-1131..its old, but at this time we cant afford a new one...the Limit control switch #169H went out and we need to replace it...since its so old is there any out there to replace this switch??? if so where can i get one??? or is there one that will interchange with this model??? Your help would be greatly appriciated...Thank you!!! Vera Bates