Help to fine model Ingenieur SL

Hi, I have been given this watch by my Father- so far I have not been able to find out the model or value (Insurance)

I believe its a Ingenieur SL (Jumbo) with an 18Kt surround but far from sure.

It has six recesses in the bezel

[](postimg.org/image/rfwk8pze5/)

[](postimg.org/image/6k02s143r/)

It does have a "bubble" glass calendar date and the strap is stainless steel.

Any help would greatly be received.

Thanks,
Poly

Hi Poly,

This is a ref. 3521 Ingenieur 'Officially Certified Chronometer'. Some info on the watch: www.moeb.ch/Ingenieur/12e_OCC.html

Hi Bas,

That's the one on the left- Many thanks for your help. Next step is to get a value.

I don't have the Box anymore so assume I would need it verify again by IWC?

Thanks,
Poly