The synthesis of LSD is not very hard, provided that you have a good organic chemistry background, and alot of first hand experience.
All of those old methods suck, big time. We have much better reagents nowadays. POCl3 dehydration? I don't think so. Thanks to the progress made in peptide synthesis over the last 20 years, we have a beautiful selection of amide coupling reagents available to us. And since this reaction is a simple amide coupling, we should use some of these gentle reagents. So all you need is your Lysergic Acid and your Diethylamine. From there I would go for the following routes:
PyBrOP coupling, catalysed by HOBt in DMF, Acetonitrile, or N-methyl-2-pyrrolidone. Used with a gentle base like TEA or DIPEA. Low temps, high yields.
You can also use a Carbodiimide coupling reagent, although the urea formed can cause problems with the workup. I would use the polymer bound ones, as the urea formed will remain bound to the solid phase, and can be removed by simple filtration.
Of course this would all be carried out at low temps, with the proper lighting precautions, etc.
As a general rule, this type of reaction can be carried out in just about any dry polar aprotic solvent, and with any coupling reagent. BOP, PyBOP, AOP, PyAOP, PyClOP, HBTU, TBTU, etc. would all work just fine.