I have an old Lyman furnace that is over 40 years old and last year purchased a Master Caster. Someone had a sale on the Lee 20 lb bottom pour and I bought one. JIC. I have never used the Lee but it is there in case I need it. But I cannot cast for long anymore so that is why I got the Master Caster. I have been thinking about using the Lee as a pre-melter for the MC. Cleatus, you might want to think about that as well. A pre-melter will give more consistency to temperature and pressure out of the spout.
BTW, I applaud your investment in the Lyman. It is unfortunate that it died so quickly but once it is working, you will enjoy using a quality unit for many years.