**Further update 15/12/2019**

The tug has been positively identified by davidships and Manfred as:
'MONTE CRASTO'
IMO 6404870

Built in 1963 by Estaleiros Navais de Viana do Castelo, Viana do Castelo, Portugal (58)
Dimensions: 28.02/25.61m x 7.40m x 3.48m
139 g.t., 24 n.r.t. Bollard pull is unknown.
Main engine: (Make unknown) 6 cylinder producing 875 bhp for 14 knots, 1 Screw.
Generator: MAN G6V30/45ATL

Ownership:
10/1963 Administração dos Portos de Douro e Leixões, Matosinhos as MONTE CRASTO (PRT flag, reg Leixões, on L-980)
1969 Sociedade Cooperativa dos Catraeiros do Porto de Lisboa, Lisbon
2004 owner wound up; sold to shipbreakers Batistas Reciclagem de Sucatas SA, Alhos Vedros and laid up
2008 broken up.

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Once identified, I will delete this image, thank you.

**Updated 13/12/2019**
Location positively identified by Luis Miguel Correia (and ably assisted by Davidships) as Leixões, Portugal.
Still working on the tug's name though..
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Assistance is sought to identify this tug and/or tug company. It has a somewhat American influenced design, perhaps?


If these can be identified, then it follows that the presently unknown location can be identified too.

The tug is alongside a Portuguese ship which has been identified as the 'Beira', IMO 5419036 and can be seen here: https://www.flickr.com/photos/patalavaca/49200316333/in/dateposted/

Scanned from a poor quality slide which was made circa 1964-1981.
Copyright owned.
From the collection of the late Niels Anker Larsen, former Danish Merchant Navy Radio Officer.

[very blurred but only one on site - DA]