This is the start of a very ambitious project for me - I intend to bricklink all of the UCS sets, buying all new parts.  However, since every UCS set has at least one unique part/colour combination and many key parts in the older UCS sets are long out of production, I intend to “refresh” each one in the same way Lego did when they updated and rereleased the 10188/75159 Death Star playset.  My goal is to change as little as possible on each model, preserve the original design and construction techniques, but replace all the hard-to-get parts with more readily available (and cheaper!) ones. I’ve been working in Lego Digital Designer, and the first set on my list is now complete: 10134 Y-wing Attack Starfighter   The original model had over a dozen unique or rare pieces which have been replaced with parts that have featured in sets released within the last two years.  Minor changes include replacing the unique copper hoses with reddish brown 6L and 4L bars and recolouring the dark orange parts to bright orange (the 1x2 brick with handle is now a 1x2 plate with handle sandwiched between two 1x2 plates).  More major changes include the 6x6x3 domes on the front of the engine struts, which only appeared in white in one other set, and have been replaced with a set of 3x3x2 white round corner bricks mounted on white 6x6 plates and held in place using concealed SNOT bricks.  The original engine pylons were constructed from technic axles covered with 7mm ribbed hoses that are now insanely expensive, so I’ve rebuilt the whole assembly using the 3L driving ring axle connector and white pin connectors (the current version has a slot in it, which is annoying but can’t really be helped). The overall length of the starfighter remains the same, but the sizes of the axles used have been altered.   One part which perhaps should have been replaced is the 30359b “Bar 1 x 8 with Brick 1 x 2 Curved Top End”, which only appeared in white in 2 sets but is relatively plentiful on bricklink (I was surprised to find one German seller with over 1500 of them in stock). However, the most significant change to the model is the replacement of the white wheels forming the engine nozzle (part 32077, unique to the set) with a brick built structure that adds some extra detail
Here, some bricks have been removed to better show off it’s construction:
  I made it as lightweight as I could, but it is still twice the weight of the original wheels .  I suspect it will cause the pylons to droop over time, and I’m worried it might be enough to throw the model off balance on its stand.  I also hate the way it’s mounted on a single axle, allowing it to spin almost freely, but the distance to the central turbine is 3 technic half-bushes so a pin is incompatible.  I'd be curious to hear suggestions for a better version. Full details of the part changes under the spoiler tag.     I've got LDD and LDraw files prepared, you can access them on bricksafe.  You can also view the model on mecabricks here. Any comments on the model, my CGI images, or suggestions for improvements would be much appreciated!   Edit 9/7/17: Migrated all photos from photobucket to bricksafe.  I am never using photobucket again...