These are most likely "acetate" discs used by home and some commercial recordings that did not need processing.
The surface is soft and easily damaged... as for cleaning dont get them wet enough that moisture can get between the coating and the inner core.
Most "acetate" recordings can be surface cleaned with Windex and wiped quickly off.
As for play back stylus I use 2.5, 2.8, 3.3 mil truncated as most are cut with wide angle cutting stylus, especially if they are recorded at 78rpm.
Hope this helps
--- On Wed, 1/21/09, Stewart Adam <[log in to unmask]> wrote:
> From: Stewart Adam <[log in to unmask]>
> Subject: [ARSCLIST] Recordisc
> To: [log in to unmask]
> Date: Wednesday, January 21, 2009, 4:34 AM
> I have 6 discs made by The Recordisc Corp. They seem to be
> made with a steel sub straight. Any
> suggestions as far as cleaning them and what type of stylus
> would be best?
> Stewart Adam
> Creative Audio Works