all you need to know
1. horizontal dropouts, check.
2. crmo, not stovepipe high tensile steel, check.
go for it.
Lotus was a well respected Japanese made brand back in the day. Their top line models were equal to anything out of Italy, with Columbus SL tubing and fittings very reminiscent of Cinelli.
Tange double butted crmo is fine yeoman grade steel.
Any lugged frame is cool, since they're getting scarcer as the years roll on.
Yours is probably built for 700C wheels, which is fine.
Even better is when you find one that meets qualifications 1. and 2. and was built for 27" wheels. Then you can fit some serious 700C fatties in it, like 35mm at least, which is great for foul weather season or fixed gearing dirt roads. But you should still be able to get some burly 28mm rubber in even if it was designed for 700C. Panaracer Pasela, I think they're called, is a real popular fatter tire, or check Nashbar they're alway blowing out 700C touring tires cheap.
I'd say you couldn't go wrong with a 42/17, or an 18t cog for dirt roads.
Don't buy any fancy boutique anything, other than a EuroAsia track cog, which has enough threading not to spin on your hub and destroy the threads. That is important, cheap thin track cogs will spin when you get on it and ruin your hub.
Use a standard road wheel with a threaded freewheel (not freehub) hub. Move the R side spacers to the L side of the axle to get the chain line, then redish the rim by loosening the R spokes and tightening the L spokes until the rim is again centered between the locknuts. Drip penetrating oil on the spoke nipples at the rim and spoke points if the wheel is old, or you could round out the nipples trying to get them to turn. Truing stand is nice, but you could do the deed right in the frame using the brake shoes, adjusted tight, as a guide.
You do NOT need a special track hub, install the track cog using liberal amount of blue 242 loctite, then reef it tight with a chain whip. I guarantee you you will not spin the cog loose, I have busted chain whips removing loctited track cogs. You can always get it off by applying heat from a soldering iron. Nor do you need a lock ring, which is the reason for track cogs. Some folks put a bottom bracket english threaded lock ring on after the track cog, and if it makes you feel good, it hurts nothing, but it is totally unnecessary if you used loctite. Track hub lock rings are reverse threaded so the cog cannot spin the lock ring off. With a BB lock ring on a road hub, and no loctite, the lock ring can still spin off as both are threaded on the same r hand threads.
I'd recommend at least a front brake. I use both, mostly because I like having two brake hoods for my hands, so might as well hook them both up to something.
Don't need no nutted axle if you use a steel-ended quick release skewer, and your hub has steel locknut faces, which most any freewheel hub will have.
With your redished wheel, the 42 ring will probably line up best in the big ring outboard position. So visit your local BMX shop for some short chainring bolts, which are nicer looking and easier to deal with than using washers on longer double-ring bolts, though that will also work, just not as sano.
