10-speed cassette alignment

My cyclocross bike uses a Shimano Tiagra 10-speed so I purchased a 105 10-speed cassette for the Neo to be able to quickly transition from trainer to ride to trainer (cassette is same part# but bike has 11-32 vs new cassette having 11-28). I attempted to purchase a 1.85mm spacer which I determined thru lots of web surfing to be what is needed to use a 10-speed on an 11-speed freewheel. The bike shop couldn't find the 1.85mm spacer I ordered from them so they gave me a 2.0mm one. 

After getting it all together and readjusting my rear derailer, I'm finding that there is still grinding on the last few small cogs. All good on the larger ones. Could this be due to the 0.15mm difference in the spacer? 

I did put a new chain on as well. Not sure if this be an influence as well...