Awhile back I featured a MOW vehicle for the SBB available as a printed shell through Shapeways, it is the design and handiwork of Peter Behnke who’s designs for numerous interesting Z are available at Shapeways.
Mr. Behnke prior to the printed Shapeway models produced small batches of nickel etched build kits for rail vehicles and industrial machines including cranes here we have four of those cranes:
1. 1944 KRUPP ARDELT Dier 1 
2. TAKRAF RDK 160 
3. TAKRAF RDK 280 
4. TAKRAF RDK 300 
Finely detailed etched kits originally delivered without assembly instructions are now available with limited instructions from Scandinavian Shops or qualitytoytrains on Ebay. Numerous filigree parts and thin metal make for some challenges, but they get easier after the first one or two as does most things. Various levels of expertise will be on display for those who take on these kits including soldering and painting skills, but most importantly prepping and bending parts before assembly.
First: orientation to the parts sheet or as one person has said looking at a puzzle with no idea how it goes together
Second: separate parts from sheet and gently sand any rough edges
Third: gently fold parts following photo guides here or in the instruction sheet provided with current purchases through Scandinavian Shops *each kit will have unique challenges and instructions will become more of a distraction from common sense as anyone may attest that assembles these intricate and delicate kits
note: best tool for bending etched metal parts is “The Bug”, it is part of my essential Z toolbox: 
The Bug is available at ZScaleMonster.com: http://www.zscalemonster.com/the_small_shop/
Fourth: soldering or super glue are the choices for assembling, I prefer solder because it is quick and gap filling
Fifth: a cleaning phase follows before painting, I use original Dawn liquid (blue) diluted in warm water and using a soft toothbrush gently go over all surfaces to clean off any debris or flux followed by thorough drying
Six: determine your paint color and either spray or brush water based paints, I do not recommend solvent based model paint for these kits, I have found it easier to apply layers of color with water based model paints and the flat surface appearance takes better to aging and weathering
Seventh: spray a diluted water based lacquer over the model to add durability to the painted surface followed by rigging the lines from hook to winding drum
Note: the kits do not provide some required parts including pulley wheels so some extra effort is required to fashion the essential parts for securing rig lines
Note: weighting the cabin is required for some cranes, test before securing cabin to deck, if it topples over maybe cement a small hex nut inside
Note: cranes can be assembled to allow the cabin to rotate on the deck of the crane, pre-drilled holes are provided, but tiny machine screws are not, I determined the placement of the cabin and soldered in place, I also soldered in place the boom which can also be assembled to move, but I do not recommend it: parts are to flimsy for continuous movement at the joint where the two meet
Note: the crane boom in all the kits is one piece featuring bending seams, I soldered all seams to ensure a solid construction, due to the nature of the parts SuperGlue will not work for this step as a gap filling material is required.
Note: soldering is easy with flux, I use water based flux applied to the area I want to solder with a toothpick, heating the material with a soldering iron makes the solder flow toward the heat and to the area to be joined *solder is not applied directly to soldering iron tip unless the area to be joined is too space restrictive *solder with a flux core is recommended with additional flux applied to the area to be soldered
Siding: the right tools make all the difference as with soldering the very best tool I have found is the Hako FX-951 soldering station, it features interchangeable tips, solder resistant pad, sleep mode with iron craddle, and multi function control box *best tool I bought in 2017!!!
