On Mon, 11 Mar 2019 18:12:25 +0000, Rob Morley
wrote:

On Mon, 11 Mar 2019 16:10:08 +0000
Mark wrote:

Thanks for the reply. Are the layout of the filament supports
important?

It may be indicative of the physical characteristics of the filament,
which may suggest its power rating by comparison with bulbs of a known
rating.

I would think that the lower the wattage, the higher the filament
resistance needs to be, therefore the longer the coil and needing more
than one or two supports. Also, because you don't know the wattage,
it's a good bet that your bulb is the same type as the one I found so
25W is your answer.
--
Dave W