The spring contacts in the bi-pin holder and the leads of the lamp tended to develop an oxide scale at the high operating temperatures, which tended to render the unit inoperable after fairly short runtimes. The adhesive used in this case is an inexpensive silica-filled sodium silicate based adhesive (read as muffler paste). The use of this adhesive was based on the fact that ultra-high temperature refractory cements are typically a zirconia filled sodium silicate based adhesive. Since I'm not looking at temperatures exceeding 500 to 600 °C or so, I opted for the less expensive silica filled option.
In the case of the above unit, the internal electrical connections are made with crimps, which have so far performed extremely well, but may still be susceptible to oxidation and scaling at extended runtimes. In the future, whenever I extend the leads on the lamps I will probably employ a spot-weld for even greater reliability,