Thanks Hasse, but I think in this case I need to use the exact scale. After all, the draft is an exact indication of length. 1/350 on a 1/400 might be just too much difference. Though it's better than the decals supplied with the Glasgow, which are at least twice as big as they should be.
I might try making my own. Trouble is, my printer won't do white numerals on clear film. I might try creating white numerals on a background that matches the hull colors of the model, then print it on white film. I'll let you know if I have any success.
If any after market decal maker is reading this, there could be a market for a sheet in various scales, Roman numerals and arabic, white, black, and metric and English.
Fred