IWC Cal. 89 crown identification

Merry Christmas, i hope you are all well.

I have this 1954 IWC Cal 89. The previous owner must have had the dial changed to an applied logo one from the 1960 / 1970s. Also the crown does not carry the IWC fish logo, but a crown signed "IV", so i have to assume it is not original to the watch. But then it is not a recent replacment crown, but seem cleary an old one. Can anyone tell me something about it? The logo is not familiar to me.

It didnt disturb me so i left it unchanged, but as I am going to sell the watch the crown should be original IWC.

For completness, i add a few more pictures of the watch. It is pretty cool with original box and warranty paper. The case back carries an inscription, as it was given by a Swiss company to an employee for 25 years of servcie back in 1954

thanks,

Stefan

thanks for the information, it is appreciated. I will have to ask the watchmaker to repalce it with a matching IWC crown, i hope it can be found.

thanks for the comment. I did some additional research in the mean while and it appears that IWC Cal. 89 dresswatches from the 1950s came with an unsigned crown. Is this your understanding as well? However quite a few examples carry the fish signed crown which seem to be later replacements.