It would appear all of them were dumped at sea as well, after use by the Home guard, some artillery schools and such.
We have had Home Guard marked Ross rifles appear for sale in Canada, I haven't researched them beyond what the sale advert said but appears that some may have survived.
My Ross sporter for example is market to a British marine unit and survived.
- Darren 1 PL West Nova Scotia Regiment 2000-2003
1 BN Princess Patricia's Canadian Light Infantry 2003-2013