smaller pyramid cup?

First topic message reminder :

Is it correct that the standard Clarke pyramid size cup does NOT fit into the burmese 3-pc lamps such as R-666 or R-671? I had the chance to buy a similar base, but was able to try a standard cup on it and the cup was too big to fit into the bowl. Are the smaller pyramid cups around? Can't say I've seen them. From the photos, it looks like they have straight sides.
Thanks,
Jno

Thanks Jim, I am thrilled with the results. Of course now I regret not buying all that they had.
Jno