the speedy movement is good enough that it deserves to be shown off. the finishing is better on the OEM 863/1863 display back models, but regardless of that, the movement should be seen.
i would encourage anyone who has a speedy to get a display back for it so you can chop and change as you wish.
here's my 321 calibre with aftermarket display back.

to be honest, i wish i could find someone to make aftermarket display backs for some of the vintage handwind movements like the 286.
best
Graham