F355 Spider - Roof Mechanism Differences 2.7 vs 5.2 Motronic?

Should be the same.

Why don't you check the online parts manuals? They are still available on most sites.

https://www.eurospares.co.uk/parts/ferrari/355-27-motronic/bodywork-lighting/top-hydraulic-control-41021

https://www.eurospares.co.uk/parts/ferrari/355-52-motronic/bodywork-lighting/top-hydraulic-control-41122

The electrics should be the same, too, apart from passenger footwell fuse panel fuse numbering.

 

e.g.
2.7 LH Secondary Cylinder P/N 65699800 (supersedes old P/N 64967300)
5.2 LH Secondary Cylinder P/N 65699800

Are they not repairable?

https://www.tophydraulics.com/82-ferrari-355-f355-spider

 

Algar shows the main cylinder part numbers as:

5.2 L/H 177767 & RH 177790

I'm not sure why the 2.7 doesn't have individual part numbers for the main cylinders.

https://algarferrari.com/store/parts/6-8-cylinder/355-group/f355-m5-2-355-f1/table-116/line-1

 

TopHydraulics.com show just one part number for years 95~99 for each side.

A second hand pair of main cylinders here.

https://www.ebay.com.au/itm/Ferrari-355-Spider-Main-Hydraulic-Ram-Cylinder-P-N-177767-AND-177790-PAIR-/123017047890

Not the best condition.