Roco make a good model of the English Electric 350hp shunter built for Nederlandse Spoorwegen. This locomotive is structurally much the same as a BR class 11 with different lamps and detail changes.
I bought one of the first-generation Roco models from Elaine's Trains last year and have finally got round to the coupling conversion. The model has built-in "Continental" loop and hook couplers but browsing through the Gaugemaster site I found Roco do a plug-in NEM socket. This is Roco part number RC100829, it isn't illustrated by Gaugemaster and it has the snappy name of "spare" on their site. So I hope posting this here is useful to someone!
The NEM sockets are set relatively far forward so a Kadee short number 17 coupler is plenty long enough, and the sockets are a nice tight fit on the shank. This is a 30-year old model - if only the UK manufacturers could make conversions so simple.
I want to keep this model in its original NS livery. The model is not terribly unprototypical for a British layout because at least one sister engine (600-series) has returned to the UK to work on the Middle Peak Railway, and anyway I'd like to keep the model close to its original condition. It runs well on a Morley "Vector" and a KPC feedback controller - it can be my staple traction for unfitted freight and departmental trains until I can get a British class 11 up and running.
Prototype information culled from the web
NS class 500 - the Dutch wikipedia entry is more helpful than the equivalent English one
Locomotive brake only
Running number by Roco is 523
Sister locomotive 521 was built in 1953 and is preserved at the Foundation Steam Train, Goes - Borsele (SGB) in South Beveland, Zeeland
Modelled in the pre-1963 condition, before installation of a roof-mounted flashing light