Imperial Eb History?

[Peach]

Here are some photos of my 1914 Boosey & Co Imperial Eb.

Question is, were they made like this through the Wars and evolved into the 60's -70's Imperials which are quite common?
This is the only one this size (same size as the later Imperials) I've ever come across.
Look at the squarer bows and slides. The later ones are semi-circular. Also the main tuning slide has a good length leg each side - modern Sovs and the later Imps have one rather short...
Any ideas?

[Highams]

Hi Malcolm,

Lovely example. I think you can put a lot of it down to the variations of being pretty much hand built.

Dear old Barrie Perrins said this about several Imperial/New Standard Euphoniums where replacement parts did not fit properley.

I have 2 SA Bandmaster Euphoniums, built in the same year, yet none of the slides/valves can be swapped.

CB