Today’s project was a clean up of the shocks for my ‘68 DT1 restoration, I used a Tusk style spring compressor’s to disassemble but they were less than optimal with these tightly wound springs and plastic internal dust covers.  I’m looking for suggestions for a spring compression tool that will work better for reassembly.  

 

Never had a problem with any shock just grabbing the eye in the vice & pulling down on the spring until the clips drop out. Same for assembly but best to have a spare pair of hands to drop them in on assembly although i've managed myself even if i've needed to lever the spring down with a screw driver to get one clip in. I guess you're not wanting to scratch anything looking at your pic--looks like new. Need the spring on softest of course for assembly. Shock in the vice horizontally not vertically by grabbing the top eye in the vice to then pull on the spring towards you. Make sure the vice it tight or you'll get it all in the tummy if it lets go, then arse over backwards. Only time that didn't work was in 1964 on my B33 scrambling [before mx was invented lol] & decided BSA B33 front fork springs were 'the go' fitted to the back shocks [someone started a rumour & i got sucked in] . So had about 6 inches of preload & i wasn't strong enough to get the clips in but got there somehow. Raced it like that & worked quite well but man it must've topped out hard haha.

 
Joe, with the help of my son to put the collets in, I assemble the shock and spring then hold it vertically with the lower eye on the floor and whilst squeezing the screwdrivers in my hands, push down to compress the spring.
Need to put the screwdrivers near the top to gain maximum compression with minimum effort and as RT325 says, put the adjusters to softest setting.
If you're worried about your assistant's fingers they can always use pliers to hold the collets.
I've done this on all my bikes including my CT1-B which has the same shocks as your DT1 and so far no dramas.
Good luck.

I used 2 cargo ratchet straps on mine, 1 on either side of the spring with a large screwdriver through the bottom eylet attach the other end of the strap to it and thats it

 

my home made compressor from old angle iron and threaded rod 

 
JGersh…Really beautiful shocks!!  Here’s a pic of my 68 shocks ready for the chrome shop and my spring compressors.

Really surprised that the plastic protectors really do their job. All shafts are spotless and all have superb rebound. Later 70s shocks get rusty shafts and lose all cushion ability.

These compressors are probably the best I’ve seen for not damaging the plastic shaft protectors. Google spring compressor on EBay. Probably where I got them.

Thanks for all the excellent suggestions gentlemen.  Springs went on with some good old fashioned muscle after I was able to get the preload adjuster into the softest position.  I found the aluminum outer body was pretty well fused onto the inner chrome dampener body.  After cleaning out 50 years of muck from the area below the spring I filled cavity with PB Blaster and let it soak for about 4 hours refilling it as it did its job.  That said it still took putting the bottom eyelet in the vice, wrapping the aluminum body with a piece of inner tube and breaking it loose with a 16” channel lock pliers.  

Petalcrazy - I suggest you do the same before cleaning up the aluminum bodies as the pliers did leave a few marks that required additional sanding.  Overall mine looked a little better than yours to start. Soaked overnight in evaporust, 0000 steel wool on the chrome and sanding to 1500 on the aluminum and the plastics.  I’m trying not to over restore as I do want to ride it when complete… 
BTW - I have the same compressors which I found a bit tight between the coils and only compress a portion of the spring.  The softest preload position was the key. 

 

JGersh...Beautiful! I have my chrome parts soaking in evaporust right now. Just cleaned all the muck out from below the springs. I know from disassembling other 70s shocks that the adjusters are stuck. PB Blaster is my choice as well. Thanks for the heads up on the aluminum. I'll follow your instructions on restoring. Love what you're doing there!

Pedal, are the chrome platers going to heat treat your springs after plating to reverse hydrogen embrittlement? It's worth asking the question if you haven't already.
Sorry, if I'm teaching grandma how to suck eggs.

Pete…Thanks for the info…The Chrome Shop has been in business for 38 years but I have yet to use them. I’ll see what they recommend. Thanks for the heads up.