Hello computermonkey
Did you get the DB retracts new? I looked for, but did not find any new DB retracts.
I've considered Springair retracts, the only downside being finding space to fit the air cylinder. I'm currently leaning towards MK retracts, as they can still be found on Japanese sites/shops- not cheap though.
I'm going to be using the OS AX 55 in mine ( actually I bought 2x Curare as I thought they were such a good deal)
Regards
Rodders