Thanks to all who replied.
No, the local Heating / Cooling supply house would not sell to me, or talk
to me. Local contractor, who listed themselfs as Mechanical Contractors,
had Yellow pages add that claimed "Well Stocked Parts Department"
Relay cost about $55.00 USD, but I am very positive is I was a H &C guy, the
part would cost no more than $32.50. Maybe even less. But such is life I
guess. Aside: The older guy behind the counter took one look, and pulled
the replacement part off the shelf with very little hunting or glancing at
the shelf labels. He called it a 90-113, and sold me an equillivant.
(24013). He seemed to have several on the shelf.
Part included 4x4 mounting plate, 120VAC to low voltage (24Vac?)
transformer, thermostate and load connections screw down plate, and high
current relay. Easy install, exept for my sore knees. Oh, and one of the
new wire nuts, yellow, from a bag of assortment of Wire Nuts, had no
insides; just the plastic outside bit.