Here's and update on my heater after I got it reconditioned. There has been talk of slow fan motors etc.
I had the core repaired, motor serviced, new coolant with a shutoff valve to the core in the summer and got a new rheostat type switch to replace a sporadic paddle switch.. It works like a charm. On high it blows like my cars fan and I can control it better with the new switch... So I guess all the effort and expense was worth it... Peter