that's not too bad, i know a few who put them/have put them (now retired one or two of them) actually in the rayburn. in the warming box with the door open and just fire it low and it's very effective. best bet often for lambs that won't take to their mum or the mum won't take to the lamb and the lamb is wet and cold and weak
TBH lambing is generally a case of different for each farmer at times but most round here lamb round about easter/april, i reckon the aim is to roughly get all/at least most out in the month of april
@Ganymede if you ever need a hand with anything be it lambing, repair/building work or anything. even just moving a load of hurdles or pallets i'm local so just give me a bell! always happy to help where i can
Cheers Ed