The replacement of the original ElAz fuze on booty German bombs by their new users, substituing a vane driven fuze, is well known.
But it appears that the opposite was also true - A 100kg Tolfavn bomb is/was on sale in a Finnish auction site, displaying a fuze pocket on its body for an ElAz fuse, while an obturator was added at the place of the original vane armed fuze.
Here's a wartime photo from the Finnish National Archives of the insertion of the original Finnish fuze in the tail of a similar 50kg bomb:
But it appears that the opposite was also true - A 100kg Tolfavn bomb is/was on sale in a Finnish auction site, displaying a fuze pocket on its body for an ElAz fuse, while an obturator was added at the place of the original vane armed fuze.
Here's a wartime photo from the Finnish National Archives of the insertion of the original Finnish fuze in the tail of a similar 50kg bomb: