Manure is definitely a green. Wood shavings are a very strong brown. I would try composting your mixture as is and see what happens, observe and adjust. In fact, if it's not freezing out, your bags of stuff are already composting. :-D

Fill up your bin and turn and check it every few days. Adjust moisture to damp, not drippy, not dry. If it gets warm but does not smell, perfect. If it does very little and there's wood left after the manure seems to be all turned to compost, you need more manure. If it smells bad, too much manure, add more browns.

The tumbler is a batch composter, so you'll need a place to 'store' additional manure/shavings. If you continually add, the batch will never get done. A simple wire mesh bin will work, or just a pile. Beware sealed plastic bags, lack of air will make it smell.

Manure is definitely a green.
Good
Wood shavings are a very strong brown.
Good
I would try composting your mixture as is and see what happens, observe and adjust.
OK
In fact, if it's not freezing out, your bags of stuff are already composting. :-D
Ah
Fill up your bin and turn and check it every few days. Adjust moisture to damp, not drippy, not dry. If it gets warm but does not smell, perfect. If it does very little and there's wood left after the manure seems to be all turned to compost, you need more manure. If it smells bad, too much manure, add more browns.
Ah-ha
The tumbler is a batch composter, so you'll need a place to 'store' additional manure/shavings. If you continually add, the batch will never get done.
Oh, yeah huh
A simple wire mesh bin will work, or just a pile.
Ok
Beware sealed plastic bags, lack of air will make it smell.
AH-HA!
Thanks for the smarts. Initially I was a bit disappointed in the ratio of P/S but I'll give it a try and just see what happens. When I had rabbits as a kid I had "The Straight Poop" - no sawdust or straw-so when I peeked in the bags I was surprised. Now it seems I may have half my work done for me. We'll just have to see. and stop being a bit too much OCD in the process :-/
Thanks loads
M.

you know you can add rabbit poo straight to the soil without it burning your plants

I will take your word on that Tannim. However it is not a good idea to bury or mix in wood shavings because of the risk of nitrogen depletion in the soil while they decompose. OK to put on top, so the rabbit poo/wood shavings would make a dandy mulch, aside from the aesthetics of looking at used rabbit bedding. :-]