I came across this apparently well known cryptic crossword with a twist but was unable to solve it. I also haven't been able to find a solution anywhere online so I was wondering if anyone here could help me finish it.  

Thanks in advance.

So my question is, can anyone solve this for me and explain the bits I was unable to figure out.

[Link to download it.](https://www.dropbox.com/s/sy0ph672nej2f8w/Providence_Pentominoes_Puzzle_Bradburn.pdf?dl=0)

My attempt so far are in the spoiler boxes if you want to try it with or without using my partial solution.

**My grid - not fully correct**

> 
> 
> ```
> 
>   *???ER?*
>   PURITANS
>   LYDIAN??
>   A?SUFISM
>   GRISLYS?
>   UONAORTA
>   EFFLUVIA
>   *LOFRHP*
>  
> ```
> 
> 
> 
> 

**My answers with my explanations:**

> 
>  **Across**  
> 
>  1. ??? - no idea  
> 
>  6. PURITANS - anagram of "aunt rips". Fits definition.  
> 
>  8. LYDIA - hidden in "sparkLY DIAmond" Fits definition.  
> 
>  9. SUFISM - end (ultimately) of belieF IS in SUM (total). Fits definition.  
> 
>  11. GRISLY - double meaning - bear & horror. Not sure what 'Reportedly' means here.  
> 
>  15. AORTA - two (articles) A around half of impORT. The heart is a vessel.  
> 
>  16. EFFLUVIA - (backed up iron) EF chimney (FLU) then not really sure on end part. Maybe answer is EFFLUENT but it fitted worse.  
> 
>  17. first letters of (initially) Reaches Home Plate  
> 
>   
> 
> **Down**  
> 
>  1. ??? - not sure.  
> 
>  2. FICUS - ficus benjamin is a species of tree, bejamin=$100. Not completely sure this answer is right.  
> 
>  3. ETA - dined is ATE reversed (wrong way)  
> 
>  4. RANI - anagram of IRAN. Not completely sure of this one.  
> 
>  5. ??? - no clue.  
> 
>  6. PLAGUE - capital of Czech PRAGUE with L replaced with R  
> 
>  7. ??? - not idea. Something with SA in.  
> 
>  10. FLOUR - FOUR (beatles number) with meaning of Last. 'Meal' is a synonym of Flour.  
> 
>  12. ROFL - hidden in useR OF Linux.  
> 
>  13. INFO - IN backwards (back) OF. 'Skinny' is synonym of information.  
> 
>  14. STEP - STEPHEN (composer Sondheim) minus HEN (fowl). 'Step' is a type of 'Measure'.  
> 
>  15. ALF - Double definition: Alf Landon & Alf the 80's sitcom. 
> 
> 
> 

Problems/Issues with my answers 

> 
>  FICUS and LYDIA don't fit together right. STEP & EFFLUVIA don't find together right. I know one such thing is allowed and a [passing comment discussing this puzzle and many others](https://tmcaylifeasapuzzle.wordpress.com/2015/08/31/jaw-dropping-puzzles/) makes me believe that FICUS/LYDIA is right and makes a ¢ symbol which fits.  
> 
>  Also fitting the words I have done into a [3x20 grid](https://en.wikipedia.org/wiki/Pentomino#/media/File:Pentomino_Puzzle_Solutions.svg) doesn't give me a partial message. 
> 
> 
>