It has been a while since I've been on the RCGROUPS web-site, but I see you are still going on with the build of the Engel U-boat.
Your work is looking very good as always, and the building of the model looks like you are getting into the final stages.
I noticed you had configured your own means of connecting the steering linkage. What you have come up with is very similar to a connector offered here in the states and which I have found to work well on my model.
Here is a link to the company and products they offer, which may be purchased over the internet and at a variety of hobby sites as well eg. (e-bay, and Amazon.com)
Looking forward to the day you take the boat to the pond.